American Gastroenterological Association Future Trends Committee Report: Effects of Aging of the Population on Gastroenterology Practice, Education, and Research

Article Outline

• The AGA Future Trends Committee: Charge and Process
• Introduction
• The Burden of GI Disease in Older Patients
  • Number of Older Patients Requiring Gastroenterology Services
  • Shift in the Prevalence and Incidence of GI Disease With Aging
• Physiology of Aging
  • General Principles of Aging
  • Cellular Aging
  • Immunobiology of Aging
  • Neurodegenerative Disease
• Aging of the GI Tract: Specific Issues Affecting Gastroenterology Practice and Research
  • Food Intake and Nutritional Status
  • Age-Associated Changes in Oropharyngeal Function
  • Effects of Aging on Esophageal Function
    • GERD
  • Age-Associated Changes in Gastric Function
    • Peptic ulcer disease (H pylori induced and NSAID induced)
  • GI Bleeding
  • Small Intestinal Function in Aging
    • Bacterial overgrowth in small bowel
  • Effect of Aging on Colonic Function
    • Diverticular disease
    • IBS
    • Diarrhea
    • Constipation
    • Fecal incontinence
    • Rectal prolapse
    • Colorectal neoplasia
    • Colon cancer screening
    • Use of virtual versus optical colonoscopy in the elderly
    • Chemoprevention of colorectal cancer in the elderly
    • Fecal DNA for colorectal cancer screening in the elderly
  • Age-Associated Changes in Hepatic and Biliary Function
    • Recognition and management of liver disease in aged patients
    • Variceal bleeding in the elderly patient
    • Nonalcoholic steatohepatitis and use of statins
    • Biliary disease
  • Effect of Aging on Pancreatic Structure and Function
    • Pancreatitis
  • Aging and GI Immunity
  • Aging and GI Drug Metabolism
• General Geriatric Issues Pertinent to Gastroenterology Practice
  • Impact of Common Geriatric Conditions on Gastroenterology Practice
    • Cognitive impairment in geriatric patients
    • Depression as a cause of GI symptoms
    • Functional assessment
    • Medication side effects
• Future Trends in Gastroenterology Practice: How Will the “Typical Day” Be Affected by Increased Numbers of Geriatric Patients?
  • Outpatient/Community Practice
    • Routine consultation and outpatient visits
    • Social issues
    • Reimbursement for physician visits
    • Current Medicare billing options for longer visits
      • Care plan oversight
      • Prolonged service
    • Reimbursement for procedures
  • Inpatient Practice
    • Inpatient procedures
      • Upper endoscopy
      • Colonoscopy
      • Colonoscopy bowel preparation in the hospitalized older patient
      • Endoscopic retrograde cholangiopancreatography
      • Percutaneous endoscopic gastrostomy tube placement
• Gastroenterology Workforce
  • Physician Supply and Waiting Lists
  • Gastroenterology Care by Generalists and Surgeons
  • Gastroenterology Care by Nonphysician Providers
• Gastroenterology Education
  • Gastroenterology Fellowship Programs
    • Inpatient care
    • Outpatient care
  • Who Should Educate the Trainees?
• Gastroenterological Research Questions and Needs
  • Esophageal Function and Disease
  • Colorectal Neoplasia
  • Colorectal Cancer Screening
  • Variceal Bleeding
  • GI Immunity
  • Drug Metabolism
  • Endoscopic Procedures
  • PEG
  • Outcomes Research
  • Diarrhea and IBS
  • Fecal Incontinence and Constipation
  • NASH
  • Pancreatic Disease
  • New Diagnostic and Therapeutic Technologies
  • Practice Management and Efficiency
• Recommendations
• References
• Copyright

Abbreviations used in this paper:  ABIM, American Board of Internal Medicine , ADL, activity of daily living , AGA, American Gastroenterological Association , COX, cyclooxygenase , GERD, gastroesophageal reflux disease , GI, gastrointestinal , IBS, irritable bowel syndrome , NASH, nonalcoholic steatohepatitis , PEG, percutaneous endoscopic gastrostomy , RR, relative risk

The population is rapidly aging as the “baby boom” cohort of adults reaches the age of 60+ years. This group differs from those previously moving through the geriatric age range. They are more proactive concerning their health and also more interested in aggressive management of their gastrointestinal (GI) problems. The current older “old” patients in the age range of 70–95 years are also becoming more interested in their health and in maintenance of function. This will drive health care expenditures up over the next 10 years, because individuals aged 65 years or older account for 60% of all medical expenditures and are the most likely to use other expensive resources such as intensive care unit beds and Medicare-funded long-term care beds.

This report has been prepared to identify issues that the American Gastroenterological Association (AGA) Future Trends Committee believes are likely to impact gastroenterology practice.

The following is a list of the 3 most important issues that were identified as being likely to impact practice in the near future.

Other issues believed to have an impact on future gastroenterology practice include the following: defining appropriate limits for screening tests for GI neoplasias, expanding research into age-specific treatments of common GI disorders in the elderly (diarrhea, constipation, gastroesophageal reflux disease [GERD], nonulcer dyspepsia), and revision of gastroenterology education and faculty continuing medical education to assist gastroenterologists in the management of patients with impairments in cognition, mobility, and mood.

Some of these issues, such as colon cancer screening, are being addressed in other reports to the Future Trends Committee. Others, such as defining standards of care and educational requirements, are already the focus of initiatives by other organizations such as the American Geriatric Society in conjunction with the Hartford Foundation, Atlantic Philanthropies, the D. W. Reynolds Foundation, and the American Board of Internal Medicine (ABIM). It is essential that the AGA be an active participant in any initiatives that are likely to impact practice, and this may be the time to review and coordinate these efforts to achieve the best results for our patients and our specialty.

At this time, there is an opportunity for the AGA to step in and take a proactive role in defining what gastroenterology is going to be for the next 10–20 years.

Back to Article Outline

The AGA Future Trends Committee: Charge and Process 

The AGA Future Trends Committee was created in 2004 to

…further the AGA Strategic Plan by identifying and characterizing important trends in clinical practice and scientific-technological developments in the world in general and medicine and gastroenterology in particular that potentially will impact the AGA and/or its members in the coming 3–5 years or beyond and to make strategic recommendations to the Governing Board on how AGA should deal with those trends and developments. These trends and developments may be economic, demographic, practice-based, scientific/technological or political in nature.

More specifically, the committee is charged with preparing a report (or reports) for the AGA Governing Board that describes the trends or developments it has identified, postulates their impact on gastroenterology practice and/or research as appropriate, and presents specific recommendations for action by the AGA in terms of policy and programs. The committee is also asked to monitor these trends and technologies as they play out over time.

In July 2004, the AGA Leadership Cabinet suggested several topics that the Future Trends Committee should address. Realizing that the committee could not realistically consider all of them, criteria were developed to prioritize the topics and others that might be added in the future. These criteria were as follows:

In October 2004, a crude Delphi process was used to determine the trends and developments that should be the focus of the committee’s work. Committee members were asked to assign priority scores to the items in the following list, which was based on the suggestions of the Leadership Cabinet and supplemented by AGA staff and others. This process was done via the mail.

Committee members were asked to score each item against each of the priority criteria noted previously using a scale in which 1 represents large effect and 3 represents small effect (on gastroenterology practice and research). The total scores of each topic were then summed and ranked. The 4 highest priority scores that resulted from this ranking were as follows:

New colorectal cancer screening and diagnostic technologies

Obesity-related disease

Aging of the population

Genomic and proteomic technologies.

Because the AGA was already investigating the ramifications of the obesity epidemic, the Future Trends Committee decided to concentrate on the other 3 topics.

The committee determined that preparing the 3 reports on its own was not feasible. Hence, it decided that it would solicit proposals from potential qualified authors to draft the reports and would modify and supplement the drafts as necessary. A request for proposal was prepared and disseminated in December 2004. The authors were chosen by the committee from among the responses to the request for proposal. The manuscripts submitted by the authors were reviewed by the committee in February 2005. Among the changes made to the draft reports was the addition of recommendations for action by the AGA. The committee also established a uniform format for the 3 reports. Revised manuscripts based on the committee’s critiques were completed in March 2005. The committee also had each report evaluated by an outside expert reviewer for completeness and to ensure that the authors had not made any egregious error that may have been overlooked.

This report describes how digestive function and diseases in the elderly differ from those of younger patients and the implications of those differences for gastroenterology practice. Recommendations were also made to the AGA Governing Board concerning the impact of the aging population on gastroenterology research needs training and practices. The extensive background against which these recommendations were developed are included in the report.

Back to Article Outline

Introduction 

There are more than 35 million people older than 65 years in the United States today, and their numbers are steadily increasing due to the aging of the “baby boom” cohort of individuals born between 1945 and 1970. Current predictions estimate that during the next 20 years, the percentage of people older than 65 years in the United States will increase from 13% to more than 20% of the population. The relative proportion of patients in the “oldest-old” group, aged older than 85 years, is also increasing at an even greater rate. The number of nonagenarians in the population will increase from 155,000 to more than 3 million in the next 15 years. This situation is not unique to the United States. Similar demographic shifts are being observed in Canada, Europe, and other Western or “developed” countries, in which life expectancies have increased from 65 to more than 80 years. Women will make up an increasingly larger percentage of the older population due to their increased longevity compared with men. This gender shift will be most pronounced in the oldest-old patients aged older than 85 years. The implications of this demographic shift are profound. Diagnosis and treatment of disease in patients older than 65 years currently accounts for 60% of health care expenditures, 35% of hospital discharges, and 47% of hospital days in the United States. Per capita federal spending on the elderly exceeds the amount spent on children by a ratio of 11:1.¹

Who constitutes “the elderly?” In the late 1800s, Kaiser Wilhelm defined “three score and five,” or 65 years, as the age for eligibility for pension. This definition has carried over into most of Western society. Geriatricians refer to the subdivision of the over-65 age group as the “young-old” (65–75 years), the “old” (75–85 years), the “old-old” (85–95 years), and the “extreme old” (95+ years). These subdivisions may have pathophysiologic significance, because several age-associated conditions, such as neurodegenerative dementias, seem to target the old-old and extreme old groups. The older groups are also at increased risk for loss of homeostatic control of bodily functions such as blood pressure, cardiovascular handling of fluid shifts and the ability to metabolize by-products and medications. This condition is likely the pathophysiologic correlate of frailty, which has been difficult to define but which many practitioners recognize instinctively in their oldest patients.

The practice of gastroenterology will be affected by this demographic change,² and the focus of training and delivery of gastroenterology services will need to address the unique problems in this patient group. Some of the issues are those traditionally addressed in current training, such as the increased incidence and prevalence of colonic adenomas and cancers in the geriatric population. Others, such as impaired mobility and function, cognitive impairment, falls, and depression, are not “on the radar screen” of practicing gastroenterologists or gastroenterology research groups. These common problems will, however, have a major impact on the ability of gastroenterologists to deliver timely, efficient, and appropriate care to older patients. Current gastroenterology training provides little or no information on how to recognize and deal with these common geriatric problems that have a major impact on the ability to deliver care. Other areas of concern include issues such as medication side effects and drug interactions that cause GI morbidity in older patients. Many medications are used clinically in patient populations far older than those in which the drugs were tested. Many drugs are tested in patient populations that do not reflect the high prevalence of common comorbidities seen in geriatric patients, such as hypertension, diabetes, and renal insufficiency. It is not surprising, therefore, that unexpected adverse side effects have resulted in the sudden withdrawal of several medications from the market during the past 5 years.

This aim of this report is to provide information on the impact of geriatric-aged patients on gastroenterology research and practice. It is not an exhaustive overview of all GI disease that can occur in older patients, but rather focuses on particular diseases and issues that will affect training and practice in the next 2 decades. Societal costs and quality of life are important components that also need to be incorporated into practice models dealing with older patients and are mentioned in appropriate sections of this report. Finally, to be useful, a report also needs to address potentially controversial discussion points; attempts have been made to address this goal in an objective and respectful manner.

Back to Article Outline

The Burden of GI Disease in Older Patients 

Number of Older Patients Requiring Gastroenterology Services 

A survey conducted by the Lewin group for the AGA³ and published in Gastroenterology⁴ used data from the National Health Interview Survey, National Hospital Discharge Survey, National Hospital Ambulatory Medical Care Survey, and Medical Expenditure Panel Survey to establish the burden of GI disease in the US population. Seventeen diseases were surveyed, and the total number of people affected was 289 million. Reducing these numbers to avoid overlap results in a burden of approximately 185 million individuals in the United States affected by GI disease yearly. This is a staggering number and likely reflects multiple occurrences of disease such as food-borne illness or diarrhea in patients during the course of a year. The percentage of patients in the geriatric age range with GI disease varies between diagnoses; however, all 17 diseases affect older patients. Some, such as colorectal cancer, pancreatic cancer, and diverticular disease, are much more likely to occur in older patients, and thus the burden is highest in that age group.

A conservative estimate of the contribution of older patients is that 35%–40% of geriatric patients (or 45–50 million individuals) will have one or more GI symptoms or health issues in any year. A large number will be related to constipation (or other problems of defecation) and reflux disease, based on office reports in primary care and specialist offices. This would result in a burden of more than 10 million office visits per year at the current percentage of older patients, which closely matches the numbers reported in a recent survey of gastroenterology resource utilization.⁵ These numbers may increase by as much as 2–3 times this amount as the percentage of individuals older than 65 years in the population increases to more than 20%. The cost of treating GI disease in older patients exceeds $300 million today and will likely increase by at least 2- to 3-fold as older patients live longer.

Shift in the Prevalence and Incidence of GI Disease With Aging 

In addition to well-described conditions such as colon cancer and GERD that affect older patients, it is becoming clear that other conditions usually believed to be present primarily in young patients are significant problems in geriatric patients. This includes diarrhea and irritable bowel syndrome (IBS) symptoms that seem to present de novo in patients older than 70 years. As the population successfully ages into the eighth and ninth decades of life, gastroenterologists are likely to see patients with longstanding chronic diseases, such as viral hepatitis and inflammatory bowel disease, occurring with higher than expected prevalence in geriatric patients. Age-appropriate treatments will need to be developed (eg, safer drugs to treat IBS and chronic diarrhea). New procedures and treatments will need to be evaluated in geriatric populations with appropriate comorbidities.

Back to Article Outline

Physiology of Aging 

General Principles of Aging 

As the “baby boom” generation reaches the geriatric threshold, new questions are being raised about the process of aging. Is decline in function inexorable, or can function be maintained throughout one’s life? Is the loss of function related to “normal aging,” or is superimposed disease the culprit? What is “normal aging”? There has been a dramatic increase in research funding available for aging research, primarily due to the fact that the answers to these questions are likely to have a major impact on the well-being and healthy aging of the world’s population for decades to come.

Physiologic changes in GI function do occur with age. Current research suggests that this process may accelerate dramatically over the age of 70 years. Women experience a rapid change in physiologic function surrounding the involution of ovarian function that defines the menopause. Although there is no comparable event during aging, there is considerable evidence that a threshold exists in the geriatric age range, beyond which there is significantly increased likelihood of impairment and disease. The actual age varies between individuals; however, most people experience this “geripause” somewhere between the ages of 60 and 75 years. The term “geripause” has been used to describe the age threshold beyond which significant changes in physiology occur that result in impaired function.⁶

Cellular Aging 

There are well-established mechanisms of cellular aging that have been described in human and animal models.⁷ These include acquisition of genetic errors, oxidant damage, the presence of replicative “clocks,” and alteration in metabolic signal pathways involved in cellular growth and repair. The concept of antagonistic pleiotropy, with expression of genes that enhance early survival and function but are disadvantageous later in life, has been used to explain the association between aging and development of cancer. Many of these models explain aging in non-GI tissues; however, it is important to point out that some questions remain. For example, errors in replication of DNA form the basis of models of fibroblast aging. The assumption that a certain number of replicative cycles will result in genetic errors cannot be translated to the human small bowel. Small bowel function, including appropriate secretion and error-free mucosal replacement, seems to be preserved with age. Some areas of the GI tract do seem to be sensitive to the effects of aging, such as the propensity of the colon to develop adenomas and colon cancer with age.

Immunobiology of Aging 

Aging affects the immune system in several ways. Aged individuals are less able to mount an immune response to a new immunogenic stimulus (such as a vaccine). This may reflect a loss of immunocompetent B cells from the marrow or lymphatic tissue.⁸ Immunosuppressive/cytotoxic T-cell numbers are also preferentially increased in rodent models of aging,⁹ resulting in T-cell replicative senescence and reduced cellular immunity.¹⁰ The latter is responsible for the well-characterized tendency of older patients to demonstrate lower rates of effective immunization with tuberculin injection and cutaneous anergy to antigens such as Candida.

Neurodegenerative Disease 

Neurodegenerative disease in the central nervous system is a major cause of morbidity and mortality worldwide in the aged population. The likelihood of developing dementia, such as Alzheimer’s disease, increases steeply beyond the age of 65 years.¹¹ Approximately 5% of individuals aged 65 years show signs of memory impairment and other cognitive loss associated with dementia; however, the percentage increases to 40% by 85 years of age. Direct costs of dementia include treatment of the underlying disease and complications associated with dementia, such as aspiration and falls. Indirect costs include lost income and productivity of family members that care for demented relatives.¹² Aging is a risk factor for development of other neurodegenerative diseases in the central nervous system, such as Parkinson’s disease, and peripheral neuropathies such as autonomic and sensory neuropathy. Age-related autonomic neuropathy results in impaired coordination of swallowing, gastric emptying, and colonic motility that can result in overt disease. More importantly, it seems to render aged individuals susceptible to superimposed effects of medications or diseases such as diabetes, with resultant severe impairment in function.¹³ Autonomic and sensory neuropathy is also implicated in the decreased visceral responses to inflammation and peritonitis observed in older patients. Serious events such as bowel perforation and other inflammatory conditions are often misdiagnosed or delayed in diagnosis due to a lack of overt peritoneal sensory responses such as guarding or rigidity.

Back to Article Outline

Aging of the GI Tract: Specific Issues Affecting Gastroenterology Practice and Research 

Age-related changes in GI function will have increasing importance for health care delivery as the number of elderly individuals increases significantly over the next 2–3 decades. The aging process per se has clinically significant effects on oropharyngeal and upper esophageal motility, colonic function, GI immunity, and GI drug metabolism. Although many essential aspects of GI function, such as intestinal secretion, are generally preserved with aging, superimposed effects of chronic diseases and environmental/lifestyle exposures (medications, alcohol, tobacco) impair GI function in older patients.¹⁴ A modest decline in gastric mucosal cytoprotection or esophageal acid clearance may be significant when superimposed side effects of certain medications or concurrent disease are also present.¹³, ¹⁵, ¹⁶ Certain age-related changes in GI function, such as constipation, are viewed as dysfunctional by patients and health care providers. Research areas that have been identified as important in aging include the pathophysiology of swallowing disorders, esophageal reflux, dysmotility syndromes, GI immunobiology, and the cellular mechanisms of neoplasia in the GI tract.

Food Intake and Nutritional Status 

Geriatric patients, particularly those older than 85 years, are at risk for decreased food intake,¹⁷ and this should be considered in any geriatric patient with significant weight loss. Mobility impairment, with inability to obtain or prepare food, is a common problem, particularly in patients in long-term care facilities.¹⁸ Functional screening for mobility impairment by asking about the ability to perform activities of daily living (ADLs) such as bathing and toileting, food preparation, grocery shopping, and mobility outside the home should be a part of the history for geriatric patients. Simple screening of ambulation by observing the gait can be helpful in documenting significant mobility impairment. The ability to obtain food should be considered in the differential diagnosis of unexplained weight loss in geriatric patients.

Loss of taste is also common in this age group and is often due to decreased olfaction rather than decreased taste sensation per se.¹⁹ Appetite is decreased in the elderly. Older subjects were less likely to be hungry after a 36-hour fast, and blood sugar levels did not correlate with the subjective sensation of hunger.²⁰ Other factors that have been identified include changes in prophagic and antiphagic endocrine hormones that occur with aging and that may contribute to “anorexia of aging.”²¹ Similar decreased food intake has been documented in animal studies in which food availability was not an issue, suggesting that aging itself may be associated with neuroendocrine changes that contribute to “anorexia of aging.”²² Finally, depression is a common cause of weight loss in geriatric patients,²³ and gastroenterologists need to be familiar with rapid screening techniques for depression, such as the 2-question depression screen outlined in the section on general geriatric conditions in this report.

Age-Associated Changes in Oropharyngeal Function 

The increasing likelihood of dental decay and tooth loss with aging has an obvious effect on the efficiency and completeness of mastication. This contributes to dysphagia, particularly when other mechanisms involved in swallowing are also impaired. Chewing and swallowing are also impaired by xerostomia, which affects roughly 25% of older patients, while as many as 50% have subjective complaints of dry mouth.²⁴ Medication side effects are a common cause, while a minority is due to specific diseases affecting the salivary glands, such as Sjögren’s syndrome. A mild loss of saliva production seems to occur with normal aging.

Oropharyngeal swallowing disorders are most commonly observed in patients with cognitive and/or perceptual dysfunction secondary to stroke or dementia or chronic neurodegenerative diseases that affect the brainstem or motor neurons, such as Parkinson’s disease, myasthenia gravis, or amyotrophic lateral sclerosis. Normal aging, however, is associated with alterations that predispose older individuals to dysphagia.²⁵, ²⁶ Videofluoroscopy shows abnormal transfer of a food bolus from the oral cavity to the pharynx in up to 60% of elderly patients without dysphagia.²⁷ Other anatomic changes in esophageal neuromuscular anatomy occur in the aged oropharynx, such as cricopharyngeal bars due to osteoarthritic spine disease.²⁸ The pathophysiologic significance of these is not clear, however, because they are seen in older patients with normal deglutition. Upper esophageal sphincter pressure gradually decreases with age and is associated with a delay in relaxation after deglutition.²⁹ It is believed that these changes are related to increased resistance to flow across the upper esophageal sphincter that reflects an age-related loss of muscle compliance. Risk of aspiration is also increased in older subjects by delayed elevation of the larynx and decreased ability to clear food from the pharynx compared with younger subjects.³⁰

After food is broken up in the mouth by mastication, the act of swallowing moves the food bolus from the oral cavity into the pharynx and esophagus. The oral and pharyngeal stages of swallowing are regulated by cortical input to medullary swallowing centers that innervate skeletal muscle groups in the pharynx.³¹

Effects of Aging on Esophageal Function 

Symptoms of dysphagia, regurgitation, chest pain, and heartburn are fairly common in the geriatric population, with a prevalence of 35% reported in the general population aged 50–79 years.³² It is difficult to show a consistent relationship between symptoms and underlying pathophysiology.²⁵ Studies of esophageal function show demonstrable esophageal abnormalities in only 20%–30% of symptomatic patients. A particular concern in the elderly is that symptoms of dysphagia are more likely to have a serious underlying etiology, such as malignancy. Elderly patients also seem to be more susceptible to complications of inadequately treated chronic esophageal disease, such as aspiration, malnutrition, and Barrett’s metaplasia.³³ Attempts at symptom analysis to identify subgroups at risk for serious underlying disease have met with mixed success.³⁴ The term “presbyesophagus” was coined to describe age-related changes in esophageal function, including decreased contractile amplitude, polyphasic waves in the esophageal body, incomplete lower relaxation of the lower esophageal sphincter (LES), and esophageal dilation.³⁵, ³⁶ The most common alteration in motility observed in older subjects was an increase in rapidity of propagation of the peristaltic wave, together with increased simultaneous contractions.³⁷ Esophageal dysmotility in older patients is more often a result of diabetes mellitus and neurologic disorders or the side effects of medications rather than aging per se.

Age-associated changes in the anatomy of the esophageal body seem to be minimal. The thickness of esophageal smooth muscle does not change with age. The number of myenteric neurons in the esophagus decreases with age³⁸; however, the functional significance of this is unclear. Amplitude of peristaltic contractions seems unaffected by aging.³⁹ Similarly, the literature contains conflicting reports regarding age-related changes in LES function. Earlier studies reported impaired relaxation or decreased contractions of the LES with aging. However, more recent reports suggest that concomitant disease accounts for altered resting pressure of the aged LES.²⁵, ²⁷

GERD 

GERD is a condition involving reflux of gastric acid into the esophagus that results in impaired motility in both young and aged subjects.⁴⁰ Risk factors for reflux-induced esophageal damage include decreased esophageal clearance, gastric factors such as decreased emptying or increased gastric pressure, decreased LES pressure, inappropriate LES relaxation, the presence of a hiatal hernia, and increased gastric acid secretion. Older patients seem to have a significant increase in esophageal acid exposure and longer duration of reflux episodes.⁴¹ This may be due to decreased occurrence of secondary esophageal peristalsis, an important clearance mechanism for refluxed acid.⁴² Other factors, such as gastric emptying and frequency of LES relaxation, are relatively unchanged with aging. Concurrent disease and side effects of medications may play a greater role in the pathophysiology of GERD in older patients.

Recent large-scale population screening for occurrence and severity of heartburn symptoms indicates that GERD is a common problem in the geriatric population. In a public health survey of 58,596 individuals in Nord-Trondelag, Norway,⁴³ in which there was a 90% response rate, the prevalence of GERD increased gradually from 22.1% in women and 25.8% in men younger than 25 years up to 37.5% in the oldest cohort of women (older than 70 years). In contrast, male respondents had a peak prevalence of 36% at ages 50–60 years and a decline to 33.8% after age 70 years. The higher prevalence in women was not explained by body mass, tobacco or alcohol use, dietary factors, or physical exercise. Previous studies have yielded prevalence rates of 20% in individuals older than 65 years, which matches that of younger populations.⁴⁴

GERD classically presents with heartburn, but older patients may present with less typical symptoms such as chronic cough, asthma, sore throat, hoarseness, and chest pain. The mechanisms for the pulmonary and ear, nose, and throat symptoms are likely due to aspiration of saliva and/or stomach contents and subsequent reflex bronchoconstriction. Unlike younger patients who are often treated without diagnostic testing, geriatric patients should undergo endoscopy because of the increased risk of complications such as esophagitis, stricture formation, or development of metaplastic Barrett’s esophagus.⁴⁵ All patients with weight loss, dysphagia, or anemia should have diagnostic testing performed, because these symptoms could be a sign of ulceration or malignancy. Barium esophagram, pH testing, and manometry can be used; however, upper endoscopy is indicated to detect esophagitis and other complications in older patients.⁴⁶

Screening and treatment for complications of GERD currently affect 18 million individuals and account for more than $15 million in health care expenditures.⁴ Various options for surveillance and treatment of Barrett’s high-grade dysplasia are available; however, the risk/benefit of prophylactic esophagectomy versus less invasive mucosal ablative techniques is a contentious topic. Older patients have a greater risk of complications from esophagectomy, and patient preference in surveys of informed subjects shows a clear preference for surveillance (70% prefer) over esophagectomy or photodynamic therapy (15% prefer).⁴⁷ The percentage of older patients diagnosed with GERD and its complications is expected to increase by at least 50% in the next 10 years. Current guidelines do not address the issue of when to stop screening in older patients; therefore, defining appropriate guidelines for initiation and termination of screening in geriatric patients with GERD and Barrett’s esophagus has major implications for public health costs and utilization of gastroenterology resources.

Age-Associated Changes in Gastric Function 

Decreased clearance of liquids from the stomach has been documented in older patients and can be exacerbated by anticholinergic medications. Aging is also associated with decreased perception of gastric distention, as measured by subjective fullness during inflation of a gastric barostat balloon.⁴⁸ Delayed emptying may prolong the gastric contact time of noxious agents such as nonsteroidal anti-inflammatory drugs (NSAIDs). This may have serious consequences, because significant age-related changes do occur in gastric mucosal defense mechanisms. These may predispose the aged to gastric mucosal injury and subsequent complications of ulceration.⁴⁹ Increased risk of gastric injury does not seem to be due to excessive secretion of agents that promote mucosal injury, because most healthy older individuals have minimal decreases in acid and pepsin output.⁵⁰ A small minority has severe acid hyposecretion (achlorhydria) associated with atrophic gastritis. This may be related to Helicobacter pylori colonization, because studies in cohorts of aged Japanese subjects segregated by birth year indicate a decreasing incidence of both H pylori colonization and achlorhydria in individuals born later in the 20th century, when presumably hygiene and socioeconomic conditions improved.⁵¹ Animal studies have shown a small reduction in gastric acid secretion.⁵² Human studies indicate that gastrin levels tend to increase with age, possibly as a compensatory response to an increased prevalence of gastric autoantibodies and H pylori colonization.⁵³ The increased prevalence of H pylori carriage in the elderly does not seem to result in increased rates of duodenal ulceration but is associated with increased risk of pernicious anemia and gastric lymphoma.

It is more likely that the increased susceptibility to gastric mucosal injury from NSAIDs in the elderly is a result of reduction in gastric mucosal cytoprotective factors such as mucosal prostaglandins.⁵⁰, ⁵⁴ Human and animal aging is associated with a significant decrease in gastric bicarbonate, sodium ion, and nonparietal fluid secretion,⁵⁵, ⁵⁶, ⁵⁷ and thinning of the mucus gel layer, particularly in H pylori–positive individuals.⁵⁸ Aging is also associated with a decrease in the basal and injury-induced rate of proliferation of stem cells in the neck of gastric glands in rats. In vivo expression and activity of several intestinal growth factors, such as transforming growth factor α and epithelial growth factor,⁵⁹, ⁶⁰ are decreased in animal models of aging. However, activation of epithelial growth factor receptor by membrane-bound transforming growth factor α in vitro is actually increased in gastric and colonic mucosa of aged rats,⁶¹ suggesting that the relative lack of activity may not be due to intrinsic inactivation.

Mucosal blood flow plays an essential role in maintaining gastric mucosal integrity. In rats, aging is associated with a decrease in basal gastric blood flow associated with impaired healing of acid-induced mucosal lesions.⁵⁶, ⁶² Impaired healing of gastric ulcers has also been associated with underlying impairment in sensory neuron function in several aging models.⁶³

Peptic ulcer disease (H pylori induced and NSAID induced) 

Geriatric patients are the heaviest users of NSAIDs, primarily for treatment of osteoarthritis pain and degenerative joint disease. There is overwhelming evidence that geriatric patients have an increased risk of complications such as ulceration, stricturing, and bleeding from use of nonselective NSAID cyclooxygenase (COX)-1 inhibitors. Surveys of physicians in the United Kingdom indicate that 38% of patients prescribed NSAIDs are hospitalized, and 4% die.⁶⁴ In response to the risks of using nonselective NSAIDs, interest focused on the use of more selective COX-2 inhibitors. Risk of ulceration during 8 weeks of treatment was decreased by use of more selective COX-2 inhibitors by approximately 50% in a trial of etoricoxib versus nonselective NSAIDs such as ibuprofen.⁶⁵ COX-2 inhibitors are prescribed more frequently than nonselective NSAIDs to elderly patients with musculoskeletal disease who have had GI complications, with a 47% decrease in the use of concomitant gastroprotective agents such as proton pump inhibitors.⁶⁶ Some studies have attributed cost savings to the use of COX-2 inhibitors. In a large, randomized survey of 6118 NSAID users in Switzerland, 294 had adverse effects from NSAIDs, primarily COX-1.⁶⁷ Costs of treatment and lost time from work were $7425.70 million (in US dollars), with 91% of costs attributed to the use of COX-1 agents. The investigators concluded that COX-2 inhibitors were 25 times more cost-effective. In the United States, costs of COX-2 inhibitors are much higher and use does not result in lower treatment costs.⁶⁸

Treatment with COX-2 inhibitors has recently been limited due to concerns that their use may increase the risk of cardiovascular complications. The risk seems to be greater in patients on high doses of COX-2 inhibitors. In studies of younger patients (mean age, 64.7 years), both misoprostol (200 μg 4 times a day) and lansoprazole (15–30 mg once a day) have been shown to significantly reduce the risk of gastric ulceration at 4, 8, and 12 weeks in patients taking NSAIDs daily.⁶⁹ Other studies of newer prophylactic agents, such as nitric oxide–donating COX inhibitors, show minimal efficacy at preventing ulcer formation and have not included geriatric-aged patients in sufficient numbers to determine whether these agents could be used successfully in geriatric patients.⁷⁰

GI Bleeding 

Acute GI bleeding is a fairly common problem in the elderly and can occur from any portion of the GI tract. However, studies of older patients indicate that 75% of GI bleeding can be attributed to upper sources (esophagus, stomach, small bowel), with approximately 50% due to NSAID use and 50% due to peptic ulcers. Approximately 20%–25% of bleeding is from the lower tract (terminal ileum, colon, rectum). Patients are usually older (mean age, 71 years vs 65 years for upper GI tract bleeding), and most often bleeding is attributed to diverticulosis. Female sex is also a risk factor, although this may be due to increased use of NSAIDs in older women with rheumatoid arthritis and other autoimmune arthritis. Studies that address prognostic factors influencing rebleeding, length of stay, and mortality have implicated age older than 70–80 years as a risk for significantly higher mortality and morbidity.⁷¹, ⁷² Continued bleeding or rebleeding are the highest predictors of mortality and morbidity in older patients, as in patients of any age. Management of bleeding in older patients should take into account the severity of the bleeding as measured by cardiovascular stability and a decrease in hemoglobin level. Older patients should be considered for early intervention using endoscopy, surgery, or angiographic vascular embolic treatment due to their reduced cardiovascular reserve.⁷¹ To avoid recurrence of bleeding, NSAID use should be avoided if possible and, if present, H pylori should be eradicated. Maintenance therapy with full doses of H₂-receptor antagonists or proton pump inhibitors is effective for reducing recurrent hemorrhage from both duodenal and gastric ulcers. Emergent operation for lower GI bleeding is required in 10%–25% of patients, usually due to difficulty in identifying or treating the source of the bleeding using nonsurgical interventions. Operative mortality is low (4%) in patients aged 70 years if appropriately stabilized and operated on without undue delay.⁷³

Small Intestinal Function in Aging 

The small intestine has a large functional reserve capacity due to the substantial mucosal surface area available for secretion and absorption. Intestinal surface area does not change after 6 weeks of age in rats. It is unclear whether the specific activity of intestinal disaccharidases and aminopeptidases is affected by aging, because both higher and lower activity have been reported in aged animals compared with youthful controls.⁷⁴ Delayed maturation and expression of brush-border enzymes in small intestinal villous epithelial cells during crypt-to-villous migration seem to be the underlying cause.⁷⁵ However, absorption of lactose, mannitol, and lipid in individuals older than 60 years is unaffected.⁷⁶, ⁷⁷ Vitamin D absorption and sensitivity are significantly impaired in aged rats.⁷⁸ This is also a concern in human studies, which have documented decreased uptake of vitamin D, folic acid, vitamin B₁₂, calcium, copper, zinc, fatty acids, and cholesterol in aged subjects.⁷⁹ Recent recommendations by the US Department of Agriculture to increase calcium, vitamin B₁₂, and vitamin D supplementation in persons older than 70 years reflect this new information. Iron is one nutrient that is usually present in overabundance in the diet for older individuals. Older patients may be at risk for diseases such as hepatic iron overload (particularly in individuals who are monozygotic for hemochromatosis), and iron overload has been implicated in some models of oxidative stress. Older men and postmenopausal women do not require additional iron unless there is superimposed blood loss or bone marrow impairment.⁸⁰

There is little evidence that older individuals are at risk for impaired absorption of most macronutrients in the absence of superimposed disease or surgical resection of the small bowel. Limited data suggest that absorption of raw and heat-treated soybeans is impaired in old rats compared with youthful animals, whereas casein, skim milk powder, and autoclaved soybean powder were absorbed equally well.⁸¹ This may have implications for older individuals who follow a macrobiotic diet. Studies of protein turnover indicate that rapidly absorbed proteins such as whey protein resulted in greater net protein gain in older subjects compared with younger individuals, although the effect disappeared if fat and carbohydrate were added to the test meal.⁸² It is not clear whether this indicates a true impairment in protein absorption or the effects of fat and carbohydrate on small bowel motility.

Aging may alter visceral chemosensitivity or hormone responsiveness, because an enhanced satiating effect of carbohydrates delivered into the small intestine by infusion has been reported in older men.⁸³ Mucosal regeneration is actually increased in aging. Crypt cell proliferation rates in all segments of the small intestine were found to be greater in aged rats compared with their youthful counterparts.⁸⁴ These studies suggest that aged animals have increased cell production as a result of a greater number of crypt cells undergoing cell division.

Minor effects of aging on small bowel motility have been described,⁸⁵ despite reports that several neuronal subtypes (substance P, vasoactive intestinal polypeptide, somatostatin, and nitric oxide containing) are decreased in aged animal models.⁸⁶, ⁸⁷, ⁸⁸ Studies in cats do not show significant effects of age on small bowel transit of radiolabeled lipids. In human studies, small bowel transit time measured by breath hydrogen testing was shorter in elderly men but not women.⁸⁹ The pathophysiology of enteric neuronal loss and efficacy of treatment of aging-associated neuropathy have been the focus of several reviews.¹⁵, ⁹⁰, ⁹¹ It is of interest that caloric restriction to 70% of normal intake prevents ileal myenteric neuronal loss in Sprague–Dawley rats up to 30 months of age.⁹² This seems to be mirrored in other studies that show a beneficial effect of calorie restriction on pathophysiologic degenerative changes in aging. It is not clear whether any benefit to neuronal function occurs in human subjects as a result of inadvertent weight loss attributed to impairment in food intake, and recommendations do not currently promote this degree of deliberate weight loss in healthy older adults.

Bacterial overgrowth in small bowel 

Minor alterations in small bowel motility, in conjunction with antibiotic use or concurrent illness, may predispose older individuals to bacterial overgrowth. Bacterial overgrowth in the small bowel is much more prevalent in older community-dwelling adults than in younger subjects. Parlesak et al⁹³ found that the prevalence of bacterial overgrowth as measured by breath hydrogen testing was 15.6% in 294 adults aged 61 years or older, as compared with 5.9% of subjects aged 24–59 years. Bacterial overgrowth was associated with significantly lower body weight, lower plasma albumin concentration, and increased prevalence of diarrhea. It is difficult to determine the causal relationship in studies that simply assess prevalence; however, treatment of bacterial overgrowth has been shown to improve diarrhea and promote weight gain.

Effect of Aging on Colonic Function 

Aging is associated with a number of diverse effects on the large intestine, including alterations in mucosal cell growth, differentiation, metabolism, and immunity. Disorders commonly observed in the elderly include colon cancer, diverticulosis, and altered bowel habits leading to constipation or diarrhea.⁹⁴ Although constipation is a common symptom in the elderly, age-associated alterations in colonic motility have been difficult to show. Some studies indicate that colonic transit slows with aging, particularly in women. Others found no significant difference in transit between young and elderly subjects.⁹⁵ Age-associated reduction in the nitric oxide–containing neurons in the myenteric plexus involved in receptive relaxation has been reported.⁹⁶, ⁹⁷ The remaining myenteric neurons may be functionally impaired. Release of the excitatory neurotransmitter acetylcholine was diminished in the colon of aged rats, an effect that appeared to be due to decreased calcium influx.⁹⁸ Interestingly, neurotransmitter release from myenteric neurons in the aged colon could be restored to youthful levels by use of calcium ionophores that bypass membrane calcium channels. Impaired calcium signaling may be a fundamental alteration in aging, because it has also been shown in peripheral sensory neurons⁹⁹ and muscle. It should be pointed out that inclusion of chronic laxative users in investigations of colonic function in aging should be interpreted cautiously, because long-term use of phenolphthalein results in loss of interneurons. Other cathartic laxatives, such as senna, do not cause significant anatomic damage in animal studies when used for up to 5 months.¹⁰⁰, ¹⁰¹

Diverticular disease 

Diverticulosis is an abnormality commonly described in the aging colon and predisposes to the subsequent development of diverticulitis.⁹⁴ By the age of 50 years, one third of Americans will have diverticulosis coli; by the age of 80 years, approximately two thirds will be affected. Most are asymptomatic, with 10%–20% developing complications such as diverticulitis or hemorrhage.¹⁰² Decreased tensile strength of the muscle wall and increased intra-abdominal pressures required for evacuation have been implicated in the development of diverticuli. Human aging is associated with an increase in collagen in the colon wall that is accompanied by a significant decrease in tensile strength,¹⁰³ which may predispose to herniation of the mucosa. Other factors include slow colonic transit and increased frequency of segmenting contractions, resulting in increased water resorption and hard feces. Decreased fiber intake likely also contributes to the production of hard feces and excessive straining, because both animal and human studies indicate that addition of fiber to the diet decreases intraluminal pressures in the colon.¹⁰⁴ According to data from the National Demographic and Health Survey (NDHS), hospital admissions and office visits for diverticulitis increased by 14% from 1997 to 2002, with 261,180 hospital admissions and 1,493,865 office visits in 2002. Emergency department visits for diverticulitis increased by 84% for the same period from 87,512 to 161,364 visits, underscoring the impact of the aging population on emergency department resources. Current management stresses the use of a high-fiber diet to prevent recurrence of diverticulitis. Approximately 20% of patients require surgical treatment, with elective laparoscopic treatment becoming increasingly prevalent in management.¹⁰⁵

IBS 

IBS is a common disorder, with 1.5–2.7 million physician visits yearly¹⁰⁶ and with women predominating (2.4–3.3 times the rate in men). Common symptoms include abdominal pain, cramping, bloating, distention, and altered stool consistency (loose or hard). A cross-sectional survey of households in the United States indicated that 40.5% of respondents had one or more of these symptoms during the past month.¹⁰⁷ Symptoms of abdominal pain and distention decrease with age in men (19.6% of men aged 18–39 years vs 7.1% of men older than 60 years), whereas elderly women continue to report significant symptoms (25.6% of women aged 18–39 years vs 20.3% of women older than 60 years). Less than half (45%) seek medical attention; therefore, the prevalence of diagnosed IBS in the population is lower. IBS is commonly thought of as a young person’s disease; however, the prevalence of diagnosed IBS in older individuals may be similar to that in younger adults¹⁰⁸ and should be considered when other causes of constipation and diarrhea are ruled out. The pathophysiology of IBS in older patients is unclear, as it is in younger patients, but may include abnormal sensory interpretation of normal motility and decreased compliance in the colon and rectum. Treatment guidelines for younger patients are used in the geriatric population, because there are little data to guide treatment in the older cohort. Serotonin receptor antagonists developed for use in diarrhea-predominant IBS, such as alosetron, should be used with extreme caution in older patients, because several reports of ischemic colitis in geriatric-aged patients resulted in withdrawal of this agent by the Food and Drug Administration in 2000. The pathophysiology of this complication may have been related to colonic mucosal damage from prolonged stasis of bowel contents and inhibition of serotonin receptors on vascular smooth muscle that resulted in vasoconstriction. In 2002, the Food and Drug Administration allowed reintroduction of alosetron for use in women with diarrhea-predominant IBS, based on data collected in younger patients showing few complications.¹⁰⁹ Probiotic bacterial preparations have been used to treat diarrhea-predominant IBS in younger patients¹¹⁰ and may prove efficacious in the geriatric population.

Diarrhea 

Paradoxically, although constipation is far more common, diarrhea can also become a problem for many elderly patients. Diarrhea is the second leading cause of mortality worldwide¹¹¹; however, in contrast to developing countries that lose far more young infants and children, 85% of mortality from diarrhea in developed countries occurs in elderly individuals.¹¹² Infectious diarrhea is a significant cause; however, many patients are never shown to have a clear infectious etiology. Diarrhea can become a chronic problem in older patients, with tremendous implications for social isolation and decreased activity outside the home. Between 1997 and 2002, the number of hospital admissions for chronic diarrhea increased 42% to 223,310 inpatients, while office visits for chronic diarrhea increased by 115% from 991,886 to 2,132,272.⁴ Approximately 40% of patients with chronic diarrhea are older than 60 years, and thus this is a significant health problem in the elderly. Despite this, expenditures in 1998 by the National Institutes of Health for IBS research were the least of any GI diagnosis, namely $8.2 million. The most heavily funded areas were chronic liver disease and cirrhosis ($218.6 million), colorectal cancer ($205.2 million), hepatitis C ($66.5 million), and food-borne illness ($57.5 million).⁴

A subset of patients may present with new-onset fecal urgency and frequency that is similar to diarrhea-predominant IBS. The onset may coincide with an acute diarrheal illness due to viral or bacterial infection; however, many patients continue to have distressing urgency resulting in considerable lifestyle impairment. Many curtail their travel and social activities outside the home for fear of fecal incontinence. The etiology is often multifactorial; however, side effects of medications that increase small bowel and colonic motility should always be considered in the workup of diarrhea in older patients. Common culprits include medications for dementia (anticholinesterase inhibitors), serotonin-antagonist antidepressants, and antiarrhythmic drugs. Small bowel overgrowth is an underdiagnosed cause of diarrhea and bloating in older patients and can result from use of medications that inhibit intestinal motility. Breath hydrogen testing and treatment with bismuth products or antibiotics should be considered in patients with unexplained diarrhea that is not related to infection or inflammatory disease. Decreased rectal compliance occurs with aging¹¹³ and may contribute to sensations of fecal urgency in these patients.

Constipation 

Constipation can be variably described as a decrease in the frequency of defecation or as increasing difficulty with defecation. The latter is usually due to either stool that is excessively hard or functional and/or anatomic conditions that prevent normal defecation. Anorectal dyssynergy or paradoxical anal contraction or inability to relax or coordinate the pelvic floor muscles during defecation is an example of the latter; rectoceles, enteroceles, and perineal descent often are a consequence of multiparity and/or difficult deliveries. Megarectum may result from impaired sensation and can lead to fecal impaction resulting from the formation of large amounts of stool in a very compliant rectum. Medication side effects often contribute to constipation, particularly narcotics and those with anticholinergic properties. Constipation results in increased stool retention times. This may have implications for carcinogenesis, because prolonged retention of carcinogenic compounds that are ingested, or formed by metabolism of precursors, may increase the risk of colon cancer. Constipation is extremely prevalent in older patients.¹¹⁴ Surveys in both the United States and the United Kingdom indicate that in individuals older than 60 years, the prevalence of constipation is 12% of community-dwelling seniors, 41% of hospitalized patients, and more than 80% of patients in long-term care institutions.¹¹⁵ This is likely a result of multiple superimposed risk factors: the effect of normal aging on neuromuscular function in the colon, mild dehydration from decreased water intake or use of laxatives,¹¹⁶ decreased mobility due to functional decline or forced inactivity due to disease or institutionalization, use of drugs that inhibit colonic motility (anticholinergic and narcotic medications), and effects of superimposed diseases that result in neurodegeneration. While some factors are not modifiable, it is important for gastroenterologists to recognize risk factors for constipation and avoid iatrogenic worsening of colonic slowing. A medication review should always be performed to identify potential culprits. Patients in long-term care facilities are particularly vulnerable to constipation due to decreased mobility and use of neuroleptic medications with anticholinergic side effects. Current recommendations stress the use of both fiber and stimulant laxatives in older patients, because fiber alone may not be effective in patients with significant colonic transit impairment and can result in fecal impaction.¹¹⁷ To avoid severe cramping or vomiting, defecation in severely constipated patients should be stimulated with suppositories or enemas before administering a stimulant laxative.

Fecal incontinence 

Fecal incontinence is uncommon in the general population (2.2%) but has a significantly higher prevalence (10%) in older patients, particularly nursing home residents and hospitalized elderly patients.¹¹⁸, ¹¹⁹ Fecal incontinence can result from fecal impaction and subsequent overflow, internal anal sphincter incompetence, decreased rectal or anal sensation, or other structural impairments in the pelvic floor or anorectal neuromuscular function due to trauma or iatrogenic damage from surgery or irradiation.¹²⁰ In younger patients, fecal incontinence and fecal impaction are most commonly seen in the setting of structural or neuromuscular disease. In older patients, the added risks of immobility and use of anticholinergic drugs can dramatically increase the risk of constipation and subsequent fecal impaction.¹²¹ Aging may be associated with a reduction in anal function in women.¹²² Healthy elderly women demonstrated thinning of the internal anal sphincter, resulting in decreased resting and maximum squeeze pressures in the anal canal.¹²³ Although thickening of the external sphincter was also observed, this did not correlate with increased ability to maintain continence. In the absence of disease, the effects of aging on male anal sphincter function seem minimal. Other pathologic factors that contribute to fecal incontinence in the elderly are the presence of neurologic disorders that may predispose to impairment in the ability to interpret the need to defecate (dementia) or in the ability to coordinate defecation (myasthenia gravis or stroke). In addition to the social costs to the patient and family, fecal incontinence significantly increases costs to long-term care facilities.¹²⁴ All patients with fecal incontinence should be assessed to determine whether increased mobilization is feasible, because immobility is a major risk factor. Medication review to identify drugs that affect colonic and rectal motility can be helpful, because both prokinetic and antikinetic drugs may worsen fecal incontinence. Drug treatment options for fecal incontinence include the following:

Surgery should be considered if incontinence is due to perineal laxity or other conditions that may be reversible. Recognition of fecal impaction is also critical to addressing urinary incontinence, because the 2 conditions are often related. Education of trainees should stress diagnosis of this condition using rectal examination and plain-film radiographs to document fecal loading. A urinalysis should always be performed to assess whether a coexisting urinary infection is also present.

Many trials of drug therapy for fecal incontinence are of limited duration, are not randomized due to small numbers of patients studied, and are not blinded. The latter is difficult when interventions such as enemas are used. Crossover trials of longer duration have been suggested by review of the current literature.¹²⁰

Rectal prolapse 

Rectal prolapse is particularly devastating in older patients, because it can lead to impaction, trauma, and bleeding. Early or minor prolapse often responds to treatment of constipation or impaction, because straining is a major risk factor for progression of prolapse. Unfortunately, severe prolapse is not likely to improve unless treated surgically. A recent review indicates that perineal repair or use of laparoscopic technique is better tolerated in the geriatric population than abdominal repair.¹²⁹

Colorectal neoplasia 

Colon cancer is a common disorder in older patients, primarily because most colon cancers occur sporadically and are associated with polyp formation. The observation that crypt cell production rate is significantly higher in colonic tissue from aged rats¹³⁰ raises the question of whether normal aging predisposes the colon to malignant transformation. The aged colon may be more sensitive to the oncogenic effects of growth factors and carcinogens. The active metabolite of the colonic carcinogen azoxymethane, methylazoxymethanol, induces a greater stimulation of ornithine decarboxylase activity and tyrosine kinase activity in aged rats compared with their younger counterparts.¹³¹ Similar results have been reported with transforming growth factor α and insulin-like growth factor I, both potent mitogens for a variety of tissues in the GI tract, including the colon.¹³², ¹³³ It is not yet clear whether changes in the expression and/or affinity of transforming growth factor α receptors or altered postreceptor events contribute to this process.

The risk of polyp formation increases significantly with age older than 50 years. Age alone should not preclude surgical intervention. A recent study of 1160 patients with colon cancer followed up from 1970 to 2000 indicated that the relative survival rate for 398 patients aged 70–95 years (70.5%) was similar to that of patients younger than 70 years (71.6%).¹³⁴ A retrospective review of 88 patients older than 80 years diagnosed with colon cancer of Dukes’ B–D between 1995 and 2000 found that 61% were deemed operable, and the in-hospital mortality rate was low at 2%.¹³⁵ One- and 3-year survival was 88% and 49%, respectively, which is comparable to that of younger patients with similar severity of disease. This also highlights the importance of colorectal cancer screening in those older than 80 years. The majority of patients in the study by Kirchgatterer et al were diagnosed during investigation of symptoms such as bleeding, anemia, or presence of a suspicious mass, at a time when screening methods did not routinely include full colonoscopy. Few Dukes’ A lesions were found (1%). Routine screening of this cohort of patients older than 80 years with colonoscopy might have increased the likelihood of detecting early-stage curable carcinoma. Concern that older patients will have worse outcomes than younger patients following low anterior resection for rectal carcinoma is refuted by studies showing that older patients have similar numbers of bowel movements (2.5 per day) and similar rates of fecal urgency (34.9%) compared with younger patients.¹³⁶

Colon cancer screening 

This issue is the focus of a separate report to the Future Trends Committee; therefore, this report will focus on issues of particular importance in geriatric patients. Gastroenterologists provide at least 60%–70% of all screening colonoscopies in the United States. The decision in 2003 to include colonoscopy performed every 10 years in low-risk patients as a cost-effective screening method for detection of colorectal cancer¹³⁷, ¹³⁸ has major implications for the gastroenterology workforce.¹³⁹ The change in policy occurred as a result of review by several groups involved in monitoring and funding public health, including the Department of Health and Human Services, which co-coordinated funding of Medicare. Studies published in 2000 indicated an alarming rate of right-sided colonic neoplasms missed by conventional screening with flexible sigmoidoscopy and barium enema.¹⁴⁰ They were performed primarily in patients in the younger geriatric age range (mean age, 60 ± 8 years); however, the results are likely applicable to older patients, because the incidence of colonic polyps and carcinomas increases with age. Older patients appear to have an increased risk of right-sided carcinomas¹⁴¹ and flat-type early lesions in the right colon that are more difficult to detect and remove.¹⁴²

The issue of colorectal polyp screening in older patients was reviewed by Miller and Waye,¹⁴³ who stressed the issue of using available data on expected life span when deciding whether to continue screening in older patients.¹⁴⁴ Table 1, based on 1990 data, shows the expected years of life at ages 70–110 years (a 71-year-old person would have 15.3 years, a 115-year-old person would have ∼0.5 years). Recent demographic data indicates that average life span has increased by 2–3 years since 1990; thus, these values are underestimates.

Table 1. Individual Life Expectancy Table

Reprinted from IRS publication #590 (1990).

This has created a new dilemma as the population ages and life expectancy increases, namely when to stop screening. Current guidelines indicate that screening colonoscopy is appropriate every 10 years starting at 50 years of age, but gastroenterologists indicate anecdotally that they are not comfortable deciding when to recommend discontinuation of screening. Previous use of age cutoffs such as age older than 80 years as a discontinuation point are not likely to be well received by the future cohorts of “baby boom” individuals, because their average life span is already near or at 80 years. Colonoscopy can be performed safely in octogenarians.¹⁴⁵ There is insufficient evidence at this time to determine whether an age cutoff for “polyp development” exists. Interim studies at 5 years in individuals found to be polyp- and cancer-free on initial colonoscopy performed after age 60 years indicate that this population appears to have a much lower rate of adenoma and colonic cancer than that expected in an unscreened or naive population.¹⁴⁶, ¹⁴⁷ These findings suggest that there may an age by which individuals could be designated as “nonpolyp formers” and thus avoid screening. This has enormous implications for societal costs, because substantial savings could be realized by reducing the number of colonoscopies in the general population. It also has implications for the gastroenterology workforce, because fewer procedures will be required. However, there are several other factors that will put considerable pressure on the gastroenterology workforce. At this time, only 30%–48% of the population at risk has actually been screened. The current number of trained endoscopists is inadequate to provide the number of screening colonoscopies required for 100% of the at-risk population. This problem was exacerbated by efforts in the mid-90s to decrease the gastroenterology workforce as a response to pressure from funding agencies such as health maintenance organizations. There was a 30% decrease in the number of gastroenterology trainees graduating from programs between 1994 and 1997, from a high of 400 trainees per year to 256 per year.¹⁴⁸ The number of screening colonoscopies required yearly for the 2.78 million Americans turning age 50 years in 1995 was estimated to be 230,000 if done every 3 years and 80,000 if done every 5 years.¹⁴⁹ This number is higher now and will continue to increase over the next 10–20 years.

Use of virtual versus optical colonoscopy in the elderly 

Virtual colonoscopy has not been studied extensively in the elderly but might be a more appropriate screening test for an elderly patient than an optical colonoscopy.¹⁵⁰, ¹⁵¹ The benefits include a procedure without sedation, although the insufflation of air into the colon during the study is often uncomfortable. The risk of perforation is certainly reduced, although there are reports of colonic perforation during virtual colonoscopy.¹⁵², ¹⁵³ There is still a requirement for a colonoscopy preparation. A wide range in the sensitivity and specificity of virtual colonoscopy has been reported, with sensitivity of computed tomographic colography ranging from 34% to 73% depending on the interpreters and the size of the lesions detected.¹⁵⁴ It is not clear whether this technique will be as sensitive as colonoscopy (near 99%) when used in the geriatric population.

Chemoprevention of colorectal cancer in the elderly 

Most studies of chemoprevention have focused on use of aspirin or NSAIDs due to the observation that patients taking aspirin or mesalamine for treatment of arthritis had a significant reduction in the prevalence of colonic polyps found with screening colonoscopy. The patients enrolled in these studies tended to be younger (age 45–70 years) and did not have a history of GI bleed or other relative contraindications to NSAID use. Currently, only use of NSAIDs has been shown to significantly decrease the relative risk (RR) of colon cancer (RR, 0.66) in patients aged 50–74 years.¹⁵⁵ The greatest RR reduction of aspirin use¹⁵⁶ was observed with advanced neoplasms (RR, 0.59 for adenomas >1 cm or villous adenomas) and with 81 mg of aspirin daily (RR, 0.81). Interestingly, standard-dose aspirin (325 mg) had no effect in this study (RR, 0.96) but was found to decrease the RR to 0.65 in a study of aspirin chemoprophylaxis in patients with previous colon cancer¹⁵⁷ with similar duration of follow-up (1 year). Other treatments, such as vitamin supplementation or decreased intake of red meat/increased intake of fish or poultry, seem to be much less effective in reducing RR (RR, 0.88–1.00) when surveyed in large population-based studies such as the Cancer Prevention Study II Nutrition cohort.¹⁵⁸

Fecal DNA for colorectal cancer screening in the elderly 

A recent study comparing Hemoccult II with abnormal DNA detection in asymptomatic patients, the majority of whom were older than 65 years, suggests statistically significant improvement in the sensitivities for colorectal cancer and adenomas with high-grade dysplasia (51.6% vs 12.9% and 40.8% vs 14.1%; P = .003 and P < .001). This improvement using multitarget analysis of fecal DNA was achieved without sacrificing specificity.¹⁵⁹ The use of DNA testing, with its increased sensitivity over Hemoccult II, may replace fecal occult studies but is a screening test used in conjunction with and not in place of colonoscopy. Its role in screening the elderly population may be to allow more precise selection of those needing therapeutic colonoscopy. The prospect of a simple, noninvasive test for cancer detection in the older population would encourage and facilitate screening for one of the most common neoplasms in the elderly.

Characteristics of the DNA tests, frequency of testing, acceptability to older patients, and other issues need to be addressed. However, this is an area of investigation that may make colorectal screening easier and more accessible for the elderly and most affected population.

Age-Associated Changes in Hepatic and Biliary Function 

There is no effect of age on conventional liver function tests, such as serum concentrations of aminotransferases, hepatic alkaline phosphatase, and bilirubin. However, dynamic assessments of liver function do show a decrease with aging. In healthy subjects, liver size, blood flow, and perfusion decrease by 30%–40% between the third and 10th decade.¹⁶⁰ Aminopyrine demethylation, galactose elimination, and caffeine clearance decrease in parallel with the reduction in liver volume and blood flow. Studies in isolated perfused livers from young adult and senescent rats show age-associated reductions of approximately 50% in bile acid–dependent and independent bile flow, hepatocellular uptake of taurocholate, and rate of bile acid secretion. Tight junction permeability and transcellular transport were modestly decreased in senescent rats.¹⁶¹

However, the senescent liver may be more susceptible to stress insult from diet, alcohol consumption, tobacco use, nutritional status, coexistent diseases, and genetic factors. Liver injury is associated with a regenerative response characterized by increased hepatocyte mitogen-activated protein kinase activity. Aged animals have an age-associated decline in mitogen-activated protein kinase activity and epidermal growth factor–stimulated hepatocytes.¹⁶² Specific impairment of intracellular transcription factors that are involved in transduction of growth hormone receptor activation have been reported in senescent mice.¹⁶³ Interestingly, mitogenic stimulation of these pathways in aged mice results in hepatic regeneration following partial hepatectomy that is equivalent to that seen in younger animals.¹⁶⁴ This has potential implications for management of hepatic resection in older patients, such as that used in treatment of solitary hepatoma. Hepatic damage may also be related to accumulation of oxidative metabolites with age, because animal studies indicate that some species have significantly increased hepatic lipid peroxidation by 23 months.¹⁶⁵

Recognition and management of liver disease in aged patients 

There are several key differences to management of cirrhosis in older patients compared with younger patients. These include increased sensitivity to salt restriction, protein restriction, and fluid overload, which may not be appreciated by gastroenterologists who have not been given specific training in geriatric hepatic disease.¹⁶⁶ Management of variceal bleeding can be particularly problematic, because the high incidence of ischemia renders use of β antagonists and vasopressin more dangerous. Recognition of encephalopathy is difficult in patients with underlying dementia, and spontaneous bacterial peritonitis is underdiagnosed in geriatric patients due to the lack of usual systemic responses to intraperitoneal infection (fever, elevated white blood cell count, guarding). Current transplant guidelines often use age as a cutoff, rather than function or cognition. Although transplantation is not contraindicated in patients older than 60 years, it is rarely performed, despite evidence that survival of patients up to 72 years of age with a transplant is comparable to that of younger individuals.¹⁶⁶

Variceal bleeding in the elderly patient 

Variceal hemorrhage is the most serious complication of portal hypertension and accounts for approximately one third of cirrhosis-related deaths. Between 50% and 60% of patients with cirrhosis develop gastroesophageal varices, and 30% will experience bleeding within 2 years of diagnosis. Current techniques stress early obliteration of varices using banding or sclerotherapy; however, there are little data to guide endoscopic treatment in the elderly.¹⁶⁷ Use of vasopressin in older patients can be dangerous due to the possibility of precipitating myocardial ischemia or arrhythmias in patients with preexisting heart disease.¹⁶⁸

Nonalcoholic steatohepatitis and use of statins 

As the population ages and becomes more obese, gastroenterologists will observe a significant increase in the number of geriatric patients referred for complications of obesity and diabetes. These include motility disorders such as gastroparesis and constipation due to autonomic neuropathy as well as liver dysfunction due to nonalcoholic steatohepatitis (NASH). More than 35% of the population aged 65 years or older are obese. Diabetes currently affects 12% of the US population, and more than 70% of affected individuals fall into the geriatric age range. It has been estimated that a further 6% of individuals in the United States have “borderline” diabetes or diabetes that has not been diagnosed because elevated glucose levels occur intermittently or have not caused significant symptoms. The latter may be particularly problematic, because there is evidence that NASH may progress to fibrosis and cirrhosis in a larger percentage of patients than previously believed. The other issue that is becoming a major problem is the difficulty of using lipid-lowering drugs, such as statins, in patients with clear indications for treatment (diabetes and known coronary artery disease) who also have NASH. Often these patients are diagnosed with NASH as a result of elevated liver enzyme levels found in screening blood tests performed before initiating treatment with the drug. Guidelines for treatment of these patients are not clear due to a lack of data on the long-term effects of lipid-lowering drugs on liver function in elderly patients with NASH. The problem is potentially enormous because approximately 20% of the population has hypercholesterolemia, defined as a total serum cholesterol level >240 mg/dL. Thirteen million people in the United States were prescribed statins in 1997, and at least 15 million additional people were candidates for statin treatment.¹⁶⁹ There is clear evidence that older patients show cardiovascular benefit from statin treatment.¹⁷⁰ However, practitioners are not prescribing statins even when indicated. Large population surveys of statin use in high-risk patients show an inverse correlation with prescription of statins in older patients at high risk for vascular disease, with the lowest rate of statin treatment in the highest-risk patients.¹⁷¹

Biliary disease 

The prevalence of cholelithiasis increases with age. Bile seems to become increasingly lithogenic as a function of aging, with precipitation of supersaturated bile and concomitant crystallization of cholesterol or calcium bilirubinate. Much of the available human data has been obtained from subjects younger than 65 years; therefore, it is unclear whether gallbladder function is altered in extreme age. Some studies have shown impaired gallbladder function in older subjects. Fasting and postprandial gallbladder volumes were increased in subjects older than 35 years, with less complete emptying following a meal observed in older individuals.¹⁷² Increased gallbladder volumes correlated with cholelithiasis; however, no difference in fat-induced gallbladder emptying was observed in either male or female subjects older than 50 years compared with younger individuals.¹⁷³ As in younger age groups, aged women may be more susceptible to impaired gallbladder contractility, with decreased contractile response to acetylcholine in postmenopausal women compared with aged men. Animal studies in aged guinea pigs suggest that deceased density of receptors for hormones such as cholecystokinin (CCK) and galanin may underlie the decreased gallbladder contractility and increased gallstone formation in this model.¹⁷⁴ Impairment in intracellular calcium mobilization and decreased muscle compliance correlated with decreased CCK responsiveness. The functional significance of these animal studies to humans is unclear, because decreased CCK responsiveness in older human subjects was apparently compensated for by increased CCK release, with no net change in gallbladder kinetics in aging.¹⁷⁵

Older patients tend to have more severe presentation of cholecystitis and complications of cholelithiasis, such as cholangitis. This may be related to the decrease in autonomic and sensory neuronal function with aging or due to delay in diagnosis for other reasons such as concerns about frailty. This increases the likelihood of conversion of laparoscopic to open procedures, with attendant increased risk of iatrogenic bile duct injury. Despite this, survival is equivalent to that in younger patients. A retrospective review of surgical biliary tract repair in a small cohort of 20 patients indicated that successful repair is possible in 85% of patients, which is comparable to that of younger populations.¹⁷⁶

Effect of Aging on Pancreatic Structure and Function 

The exocrine pancreas possesses adequate reserve to maintain normal digestive capacity with aging. While there are some contradictory reports, there is little evidence for clinically significant decreases in pancreatic exocrine function in the elderly human.¹⁷⁷ Age-related changes in pancreatic anatomy and histology include decreased pancreatic weight after the seventh decade in humans, with ductal epithelial hyperplasia, interlobular fibrosis, and acinar cell degranulation.¹⁷⁸ A modest decrease in bicarbonate and enzyme output in response to secretin and caerulin (a CCK receptor agonist) in elderly subjects compared with their younger counterparts has been reported. However, secretin- and caerulin-mediated stimulation of sphincter of Oddi motor function and pancreatic bicarbonate, enzyme, and volume output were not significantly changed in individuals older than 60 years.¹⁷⁹, ¹⁸⁰ In contradistinction to human studies, animal models of pancreatic function do show significant effects of aging on trophic response to hormonal stimulation. Caerulin and secretin administration increased pancreatic weight, protein content, messenger RNA expression, enzyme concentrations, and polyamine concentrations in young and aged rats, but the magnitude of the responses was significantly greater in young rats.¹⁸¹ The pancreas of aged animals shows a diminished capacity to increase pancreatic lipase and amylase content in response to a high-fat or high-carbohydrate diet.¹⁸² Given the significant reserve capacity of the exocrine pancreas, the clinical significance of these observations to healthy aged individuals is questionable.

Pancreatitis 

In about 75% of patients, acute pancreatitis does not progress beyond the stage of edema and fatty necrosis, and the disease has a mild, uncomplicated course. The incidence of acute pancreatitis in Western countries is about 10–20 cases per 100,000 per year. About half of these patients are older than 60 years, and the estimated incidence in the geriatric population is about 5–10 cases per 100,000 per year. Peak incidence in older patients varies in studies from ages 60–80 years. Little data are available for patients older than 80 years; therefore, the incidence may be underestimated in this oldest group. The prevalence is slightly higher among women, probably due to a higher incidence of gallstone-related pancreatitis. Gallstones are the most frequent etiologic factor in acute pancreatitis in the geriatric age group, being present in up to 60% of patients, with the remainder being idiopathic (25%) and other causes (surgery, drugs, trauma, and infections). In contrast, alcohol abuse is far more common in younger patients (30% vs 5% in patients older than 60 years). The mortality rate in the geriatric population is about 20%, which is twice that of the general population. Death in the elderly from pancreatitis is usually due to severe multiorgan failure. There are very little data in the literature specifically addressing the issue of chronic pancreatitis in the elderly; thus, diagnosis and management are currently based on guidelines for younger patients.¹⁸³, ¹⁸⁴

The incidence of pancreatic cancer is increasing, particularly in patients older than 65 years. Diagnosis is usually made late in the course of the disease, when curative resection is not an option. Older patients appear to have poor outcomes following surgery for pancreatic cancer. In one series of 273 patients evaluated between 1983 and 1995, 104 underwent surgical resection, with 47 patients aged 64–74 years and 19 older than 74 years.¹⁸⁵ The highest morbidity and mortality from pancreatic resection was observed in the oldest patients (age older than 74 years), and median survival was only 11.4 months versus 25.1 months for patients aged 64–74 years.

Aging and GI Immunity 

The elderly are relatively susceptible to infections that enter the body via the GI tract, and this raises the question of whether aging impairs mucosal immunity. The GI mucosal immune response in the small intestine is a complex process that involves a series of events: antigen uptake and presentation of antigen at the mucosal surface by specialized epithelial cells (M cells) overlying Peyer’s patches in the small intestine, differentiation and migration of immunologically competent lymphocytes to the lamina propria, regulation of local antibody production in the intestinal wall, and mucosal epithelial cell receptor–mediated transport of antibodies to the intestinal lumen. The effect of aging on the first 2 steps, antigen uptake and presentation, is unclear.¹⁸⁶ In rats, there was no change in the number of Peyer’s patches or the yield of lymphocytes per patch in small bowel. Increased T-suppressor/cytotoxic lymphocytes could explain the observed decrease in lamina propria immunoglobulin (Ig) A plasma cells, due to decreased cytokine-mediated differentiation of B lymphocytes by helper T cells.¹⁸⁷ Animal studies also confirm that IgA plasma cell recruitment into the lamina propria is decreased in rats and macaque monkeys.¹⁸⁸ Human studies have shown a significant decrease in T lymphocytes and mast cells in the rectal mucosa in normal individuals aged 55 years or older that was not reflected in other mucosal cell populations, such as neuroendocrine cells.¹⁸⁹ Thus, the third step, differentiation and migration of lymphocytic immunoblasts into the lamina propria, seems to be decreased with aging. Interleukin-2 production in lamina propria lymphocytes and intestinal IgA production is decreased in aged subjects.¹⁹⁰ A tissue-specific, age-associated reduction in transport of polymeric IgA across rat hepatocytes may be the result of decreased synthesis of polymeric Ig receptor or diminished microtubule-dependent translocation of the receptor-ligand complex.

Data from the National Hospital Discharge Survey from 1979 to 1995 indicate that the total number of admissions for gastroenteritis decreased by 38%, mostly due to a decrease in the younger groups. Hospital admissions actually increased in those aged older than 75 years during this same period.¹⁹¹ The increase in incidence and severity of GI infectious diseases in the elderly may represent a relative immunodeficiency state of the GI immune system. Other factors that probably contribute to an increased risk of GI infection in older patients include improper food storage, decreased taste and smell (problems identifying contaminated food), dementia, reduced gastric acid, and colonic slowing. Diarrhea causes significant morbidity and mortality in older individuals, with 51% of deaths due to diarrhea in the United States occurring in patients older than 75 years. In addition to decreasing exposure to infectious environmental agents, novel interventions aimed at improving GI immunity may have a significant impact on morbidity and mortality caused by infectious disease in the elderly.

Aging and GI Drug Metabolism 

An evolving area of interest to clinicians and investigators is the field of age-associated changes in drug metabolism. Elderly patients are at increased risk for drug interactions and adverse drug reactions, primarily due to known side effects of the large number of drugs prescribed in this age group.¹⁹² The cytochrome P450 system plays an essential role in drug metabolism in humans. The CYP3A subfamily expressed in the GI tract and liver is the most abundant form of hepatic cytochrome P450. It oxidizes a wide variety of clinically and toxicologically important agents, including endogenous and exogenous steroids, and activates procarcinogens such as aflatoxins. CYP3A metabolizes numerous drugs, including calcium channel antagonists, immunosuppressant agents, cholesterol-lowering agents, benzodiazepines, nonsedating antihistamines, and macrolide antibiotics. The divergent structures of the drugs metabolized by CYP3A indicate a broad substrate specificity of these enzymes, which contributes to adverse effects reported with the concomitant use of antihistamines, macrolide antibiotics, and prokinetic drugs.¹⁹³

High levels of CYP3A activity in both the intestinal epithelium and the liver result in significant first-pass metabolism of oral medications. Cyclosporine has a low oral bioavailability, not due to poor adsorption but due to metabolism in the intestinal epithelium that decreases the ratio of drug transported into the circulation to 60% of luminal concentrations, followed by hepatic metabolism that allows only 30% of circulating drug to pass into the systemic circulation. In other words, CYP3A-mediated metabolism of cyclosporine results in bioavailability of only 18% of the ingested dose. CYP3A activity is reduced by 25%–50% in aged individuals.¹⁹⁴, ¹⁹⁵ Other features of CYP3A expression that are relevant to the clinician include a marked (5- to 20-fold) variability in activity between individuals that is determined by both genetic and nongenetic factors. Superimposed liver cirrhosis may reduce CYP3A activity by 30%–50%. CYP3A activity can be modulated by inducers such as rifamycin and anticonvulsant agents and by several potent inhibitors such as azole antifungal agents and macrolide antibiotics. Therefore, the potential for drug interactions with these medications and other CYP3A substrates, when given together, is significant. There is considerable effort devoted to developing in vitro and in vivo techniques that will facilitate the identification of potential drug interactions whose clinical significance can be subsequently assessed.¹⁹⁶ For example, CYP3A catalyzes the N-demethylation of erythromycin that has led to the development of a noninvasive [¹⁴C]erythromycin breath test.

Back to Article Outline

General Geriatric Issues Pertinent to Gastroenterology Practice 

Impact of Common Geriatric Conditions on Gastroenterology Practice 

Gastroenterologists who treat older patients (most gastroenterologists other than pediatric gastroenterology specialists will treat geriatric patients) need some understanding of the concept of geriatric care. Geriatric medical care differs from medical care in younger adults in that the focus is often on preservation of function and improving quality of life, rather than on investigating, diagnosing, treating, and “curing” specific diseases. All physicians who treat older patients need to have some understanding of social and psychological problems that impact treatment, including awareness of family or caregiver support. Specialists are often not equipped to assess function or to provide social interventions, because they do not usually work as part of a multidisciplinary team that includes social workers and other nonmedical professional staff. There may be substantial benefits to inclusion of nontraditional groups such as social workers into a gastroenterology practice that has a large number of older patients.

There is tremendous heterogeneity in the older population in terms of function, cognition, and comorbidities, which affects medical decisions and quality of life. Older patients with multiple chronic diseases are more interested in maintaining function and independent living rather than freedom from disease. Older patients are at high risk of iatrogenic complications due to conflicting treatments by different providers, and communication between providers is essential.

Geriatric patients often present with symptoms that are not “typical,” such as fatigue and anorexia, which may be due to a variety of causes, such as pneumonia, urinary infections, or myocardial infarction. More classic symptoms, such as cough, dysuria, or chest pain, may not be present. Gastroenterologist training should emphasize these differences. Patients with mild cognitive impairment are at high risk of developing delirium when ill or undergoing interventions such as endoscopy that require sedation. Family reports of baseline cognitive function can be extremely helpful in these circumstances, as can baseline data concerning functional status and dependence on assistance for their daily activities. These records should be available to specialists in an easily obtained and understandable format. Computerized records are improving the ability of gastroenterologists to access this type of information, and future practice models should include use of this type of information.

Cognitive impairment in geriatric patients 

Cognitive impairment is rare in those younger than 60 years (2% have cognitive impairment) but increases exponentially to exceed 40% by age older than 85 years. Dementia impacts the ability of the patient to provide a history or cope with a treatment plan.¹¹, ¹⁹⁷ Although gastroenterologists do not routinely perform tests of cognition, they should be aware of the types used and what the scores mean. This kind of information may be available in other medical records and should be reviewed in older patients. Training programs should include information on the most common type of cognitive screening, using the Folstein Mini-Mental Status Examination,¹⁹⁸ which takes about 5 minutes to administer and is scored out of 30. A score of 25 or less usually indicates a cognitive problem, such as dementia or delirium (or occasionally depression). The Mini-cog test is a very rapid screen for memory impairment in which the patient is asked to remember 3 items, draw a clock, and then recall the items. The test takes 1–2 minutes, does not require medical training to administer, and has a sensitivity to detect impairment exceeding 99% and a specificity of 90%.¹⁹⁹ These tests can assist nongeriatricians to document intact cognition for medicolegal purposes, such as when obtaining consent for procedures.²⁰⁰ Dementia is a significant risk factor for hospitalization, and demented patients account for significantly greater Medicare expenditure compared with nondemented patients. A large-scale survey of Medicare beneficiaries aged 65 years and older (n = 1,238,895) showed a prevalence of dementia of 8.3% (n = 103,512). Demented individuals had incremental costs of $6927 or 3.3 times that of nondemented individuals, with 54% of costs due to hospitalization (adjusted odds of hospitalization, 3.68).²⁰¹ This may be due to inability to comply with treatment and is also likely related to impairment in function, particularly in ADLs, that limits the ability of the patient to cope with superimposed morbidity.

Depression as a cause of GI symptoms 

Depression is the most common psychiatric disorder in the general population, affecting 1% of all individuals. It is more common in older patients, with a prevalence of 3%–7% in most studies.²⁰² Older patients often present with anhedonia, social withdrawal, and somatic symptoms such as nausea, abdominal pain, and weight loss. The latter can be very confusing and concerning in patients with underlying risks for neoplasia, and most patients referred to a gastroenterologist with these symptoms will undergo a workup to exclude neoplasia. Obviously the presence of a disease such as cancer can be a risk factor for subsequent depression, as has been shown in studies of patients with colon, breast, lung, and prostate cancer.²⁰³ It is important for gastroenterologists to have some ability to recognize that depression may be contributing to GI symptoms in older patients. A high index of suspicion and the judicious use of rapid screening tests for depression, such as the 2-question depression screen,²⁰² is an efficient way of making the correct diagnosis in these patients.²⁰⁴

Functional assessment 

Information concerning the patient’s ability to perform ADLs such as eating, walking or transferring, toileting, dressing, grooming, and bathing needs to be available for review when a treatment plan is being arranged. A patient who cannot perform their ADLs cannot be left alone for even a few hours. An inability to perform other tasks that can be delegated, such as driving, obtaining groceries, or preparing meals, does not preclude patients from living alone. However, complete independence requires that patients either perform these “Independent Activities of Daily Living” (IADLs) themselves, or obtain assistance from family or other social supports. Although gastroenterologists may not believe that documentation of these functional tasks is their job, lack of knowledge concerning problems performing them may make it impossible to treat the patient at home or even send the patient home from the hospital. ADL impairment also is an independent risk factor for hospital admission in the elderly patient.²⁰⁵ Gastroenterologists do not routinely document functional impairment, including risk of falls, which may have medicolegal implications for recovery from sedation used during endoscopic procedures.

Medication side effects 

Most medications used by gastroenterologists have never been tested in patients older than 75 years and in patients with the usual chronic medical problems of aging (hypertension [present in 70% of patients older than 75 years]), diabetes, heart disease, arthritis, and osteoporosis). Despite this, patients older than 70 years have the highest incidence of prescription and over-the-counter drug use and the highest incidence of serious adverse reactions.¹⁹² Drugs with anticholinergic side effects (neuroleptics, tricyclic antidepressants, antihistamines) have both GI and central nervous system side effects that contribute to constipation, swallowing disorders, gastroparesis, and confusion in older patients. Narcotics and other drugs that inhibit motility are a common risk factor for constipation. Several other classes of drugs also can cause GI problems in the elderly, including proton pump inhibitors (diarrhea) and antiarrhythmic medications (diarrhea and nausea).

Back to Article Outline

Future Trends in Gastroenterology Practice: How Will the “Typical Day” Be Affected by Increased Numbers of Geriatric Patients? 

Outpatient/Community Practice 

Routine consultation and outpatient visits 

Given the higher incidence of chronic disease and comorbid illnesses in older patients, it is unlikely that the current gastroenterology practice model of short office visits (5–15 minutes) will remain feasible. Longer visits have been shown to improve outcomes in complex patients with other chronic conditions such as asthma.²⁰⁶ Little data exist in the current literature to guide gastroenterologists in how to address the issue of the increasing complexity of medical care and living arrangements of geriatric patients. Coordination of care, including home visits by nonphysicians, is not a model with which most gastroenterologists are familiar. The time factor will need to be researched adequately and included in any recommendations for physician utilization schemata and reimbursement issues.

Because older patients are almost always on multiple medication regimens, gastroenterology practices must establish a method for obtaining and reviewing the patient’s medication history on each visit. This activity may be conducted by qualified nurses or other health care professionals.

Social issues 

The outpatient living arrangements of the elderly patient need to be documented, because this can have a major impact on feasibility of treatment. Working with the older patient often requires patience. Caregivers need to speak clearly and make sure that the patient can hear and understand. Safety issues, such as leaving an unsteady patient alone on the examination table, can result in injury and risk of legal action. The family is an important source of accurate information about how the patient is managing. In particular, gastroenterologists need to be aware that patients may minimize difficulties in an attempt to be independent. Because caring for elderly relatives can be very time-consuming, gastroenterologists need to be able to recognize signs of caregiver stress in the family and have a plan to address this. A full medication list is crucial, and many practice settings do not obtain a current, accurate list of all medications taken (including herbal and over-the-counter medications). A “brown bag request” to bring all the medications with them to each visit can be extremely useful. More efficient use of administrative staff and nurses to obtain information and documentation may be a method to help gastroenterologists deal with the complexity and time demands of older patients.

Reimbursement for physician visits 

The economics of evaluating and treating elderly patients has been an ongoing issue in specialties such as geriatric medicine, in which the majority of patient reimbursement is through Medicare. The reimbursement rates are reviewed every 5 years and set by the Centers for Medicare and Medicaid Services based on section 1848(C)2(B) of the Omnibus Budget Reconciliation Act of 1990.²⁰⁷ The relative value units (RVUs) for Medicare reimbursement are generally lower than those offered by most private insurance policies. An additional concern voiced by many groups that are facing an increase in geriatric-aged patients in their clinics is the perception that older patients take more time for an office visit and that this will also decrease revenue significantly. There is also concern that the prospective Diagnosis-Related Group system used to determine reimbursement might be inequitable for groups that take care of a large number of older patients with GI admissions.²⁰⁸ Patients older than 70 years had higher hospital costs, longer length of stay, and a higher rate of intensive care unit and transfusion utilization. The greatest losses to the hospital were seen in the group older than 85 years, with average losses of $2235 per patient in 1987. This is likely due to the fact that, while the Diagnosis-Related Group system stresses age as a primary factor, comorbidity is a more powerful predictor of hospital use than age.²⁰⁹ Dementia, which in 1991 was not recognized as a valid comorbid condition, was found to be a much stronger positive predictor of hospitalization than age. Therefore, it may be timely to review Medicare reimbursement of gastroenterology care, with consideration of the role of comorbidities and functional status in defining complexity.

The first point to be made is that gastroenterology practices should review the complexity of the patients they treat and determine whether their billing takes into account activities such as review of test results, review of other medical records, and management of other comorbidities during the office visit. These options increase the complexity of the visit and may result in more favorable reimbursement for complex consultations. This is an area that specialist billing advisors such as the AGA Coding Staff could focus on, because it requires no revision to the current billing structure. Unfortunately, there are little data in the literature specifically applicable to gastroenterology practice. Family medicine has seen an increase in the complexity of patients in general practice, with an average of 3 problems for younger patients and 3.88 for patients older than 65 years.²¹⁰ Interestingly, an average of only 1.9 problems were listed on the bill and presumably reimbursed. A strong case can be made that comorbidities have changed the demographics of patients seen in primary care settings.²¹¹ Of the top 4 diagnoses in the 2001 National Ambulatory Medical Care Survey, 2 are primarily geriatric diseases (hypertension and arthropathies), while acute upper respiratory infection is more likely to result in hospitalization in older patients and the prevalence of diabetes is increasing rapidly in the elderly.²¹²

Current Medicare billing options for longer visits 

Care plan oversight 

There are currently 2 billing options under Medicare that attempt to address the issue of reimbursement for patients with multiple health problems. One is the “Care Plan Oversight” service, which applies to physicians who coordinate care for patients receiving services from home health agencies. The benefit allows physicians who spend a minimum of 30 minutes per month coordinating care to bill for a monthly charge. Documentation must reflect the time spent and the activities involved in coordinating care. This would not likely fit the consultant practice model of most gastroenterology groups but might be useful for gastroenterologists who have geriatric patients with chronic GI conditions requiring frequent monitoring. Conditions in younger patients that have traditionally required frequent gastroenterologist or hepatologist visits include liver transplantation, chronic liver disease secondary to viral and other hepatitides, and inflammatory bowel disease. As the cohort of patients with these conditions age, clinics that monitor these patients should consider whether their practice is in fact delivering this kind of oversight and bill accordingly.

Prolonged service 

Individual visits that result in a significant amount of “face time” between the gastroenterologist and patient can be billed as “Prolonged Service” in addition to the standard Evaluation and Management code for the particular diagnosis and complexity of the visit. This option (code #99354) is based on the direct face-to-face time with the patient and requires supporting documentation of the initial hour and every 30-minute increment over that time (code #99355). Analogous codes are also in place for inpatient visits, record review, and standby time for procedures. Unfortunately, the option is of limited utility to most gastroenterologists, because it requires a visit that includes at least 1 hour of direct face time with the clinician. Specialties that use this option require a verifiable method to document time spent by the clinician, which has traditionally been the clinical note coupled with “standard practice models” such as geriatrics, which is assumed to require more time per patient. It is likely that gastroenterologists would have to provide more rigorous proof of time spent, because the standard practice model assumes short return visits (15 minutes or less). The AGA should look into this reimbursement, particularly the practicalities of documenting time spent. Endoscopists already document time by recording the time at the start and end of procedures, and a similar strategy could be used in office visits.

Reimbursement for procedures 

Introduction of Medicare reimbursement for screening colonoscopy in 2001 resulted in a significant increase in the number of colonoscopies performed,²¹³ particularly in older patients. There was a 55% increase in the percentage of colonoscopies performed for screening and a 112% increase in the total number performed. Mean age of patients increased from 56 ± 9 years to 62 ± 10 years, and the number of low-risk individuals with polyps (24%) was similar to that of patients at higher risk due to a positive family history (21%). This increase is an appropriate response to the goals of the change in legislation, which were to increase the rate of colorectal cancer screening in the general population and improve the detection rate of early neoplasia. Perceived inequity between private insurance reimbursement and that of Medicare has not appeared to play a major role in the decision to perform screening colonoscopy, and workforce numbers may be the limiting factor in delivery of screening colonoscopy at this time. At this time, the Centers for Medicare and Medicaid Services are reviewing reimbursement for upper endoscopy and sigmoidoscopy that include biopsy or endoscopic treatments, and similar review may be needed for procedures in older patients.

Inpatient Practice 

As outpatient care and services improve, inpatients are becoming sicker with more comorbid, chronic diseases than they were in the past. The majority of inpatient hospitalized care occurs during a person’s last year of life. As the population ages, the proportion of geriatric-aged patients in the hospital will increase substantially, and the complexity and acuity of a hospitalized patient cared for on gastroenterology services will increase. Hospital-based gastroenterologists may be the new model for caring for elderly GI inpatients, similar to hospital-based internists that have evolved over the past 10 years. Any practitioner who cares for inpatients will need to be aware of the special risks posed by the elderly patient regarding (1) fluid overload in the setting of cardiac, pulmonary, or renal disease; (2) medication interactions and side effects; (3) the impact of depression and dementia on treatment; and (4) quality-of-life issues and appropriate interventions.

Inpatient procedures 

Endoscopists performing procedures on elderly patients must be aware of the higher rate of complications due to concomitant diseases, a decreased normal physiologic response, and an increased sensitivity to adverse drug effects and multiple drug interactions. Often a less invasive endoscopic approach is justifiable and preferable to surgical intervention in this age group. Interestingly, in a review of all endoscopy-related deaths in Scotland in 1999 (153 of 33,854 procedures), age was not identified as a risk factor. High American Society of Anesthesiologists (ASA) grade, use of intravenous sedation, and lack of available oxygen therapy or cardiovascular monitoring were all associated with increased risk of death.²¹⁴ Elderly patients often require less sedation than younger patients and should be monitored closely with use of blood pressure and oxygen monitoring.²¹⁵ Continuous oxygen supplementation during a procedure and the recovery period will prevent oxygen desaturation but must be used cautiously in patients in whom the risk of co₂ retention is high.²¹⁶ In 1991, the US Food and Drug Administration and the American Society for Gastrointestinal Endoscopy reviewed cardiopulmonary complications related to sedation. In more than 21,000 procedures, cardiopulmonary complications occurred in 5.4/1000 with death occurring in 0.3/1000. This represented 40% of all complications reported.²¹⁷

Upper endoscopy 

Upper endoscopy is safe to perform in elderly patients, but care must be given to proper positioning, especially in patients with cervical arthritis. Direct visualization during intubation of the esophagus is mandatory, because elderly patients have an increased incidence of a Zenker’s diverticulum.²¹⁶

Colonoscopy 

Data concerning potential problems with colonoscopy in elderly patients indicate that patients aged 70 years or older were less likely to have a successful full colonoscopy to the cecum than younger patients (78% vs 93%).²¹⁸ Unfortunately, elderly patients were more likely to have abnormalities than younger patients (74% vs 60%). A prospective study with 180 patients concluded that colonoscopy is more difficult in patients older than 60 years but that they tolerate the procedure significantly better.²¹⁹, ²²⁰ Rex et al reported that elderly patients, especially men, are more willing to undergo a colonoscopy without sedation.²²¹

Colonoscopy bowel preparation in the hospitalized older patient 

Geriatric patients have difficulty taking the laxative preparations used to cleanse the bowel.²²² Patient and physician reports of fecal incontinence and accidents due to impaired mobility, particularly those of falls and hip fractures sustained while trying to get to the bathroom, seem to have an impact on patient willingness to undergo colonoscopy. This may be particularly problematic in the hospital setting, because patients are more impaired due to illness and at greater risk of falls. The combination of intravenous and oral fluid delivery increases the risk of fluid and electrolyte imbalance. Hospitalized patients are likely to have a higher prevalence of coronary disease (both recognized and unrecognized) and heart failure, which can increase the morbidity and mortality of endoscopy.²²³ Age-related colonic slowing also seems to decrease the efficacy of bowel cleansing; however, regimens that use polyethylene glycol solutions result in less nausea and better cleansing than sodium phosphate.²²⁴ The standard regimen of rapid cleansing over less than 24 hours may not be optimal in older patients with superimposed neurodegenerative disease and antikinetic drug use and is an area for future research.

Endoscopic retrograde cholangiopancreatography 

Gallstones and their associated complications are more common in elderly patients. Complicating the issue is that elderly patients may present with a subtle clinical picture that is not recognized as an abdominal or gastroenterologic emergency, such as cholangitis presenting as an acute confusional state with minimal or no abdominal pain. The likelihood is that urgent or emergent endoscopic retrograde cholangiopancreatography is more likely to be required in elderly patients.

Endoscopic retrograde cholangiopancreatography is safe to perform in elderly patients, and indeed endoscopic sphincterotomy, stone extraction, and stent placement are safe and effective. Depending on underlying comorbidities, endoscopic treatment alone may be the most prudent option. When considering therapeutic options in elderly patients, surgical and nonsurgical options need to be considered.²¹⁶, ²²⁵

Percutaneous endoscopic gastrostomy tube placement 

A frequent request for gastroenterologists is that of percutaneous endoscopic gastrostomy (PEG) tube placement in elderly patients who are unable to obtain adequate nutrition due to neurodegenerative diseases such as Parkinson’s disease or impaired swallowing. PEG tubes may play a role in treatment of selected patients, such as those with gastric obstruction due to malignancy.²²⁶ The goal of tube placement in this situation is palliative decompression of the stomach, because the median survival of such patients is approximately 8 weeks. Although useful in selected situations, some studies have suggested a higher than expected rate of complications and death related directly or indirectly to PEG tube placement. A community practice with 150 patients showed a 22% 30-day mortality and 50% 1-year mortality. Although the high mortality was deemed mostly secondary to the underlying diseases, most patients did have symptomatic problems directly related to the PEG tube.²²⁷ This study underscores the urgent need to be able to identify appropriate patients for PEG tube placement and not to just perform this procedure simply “to keep the patient alive.” Current Medicare reimbursement to nursing homes actually encourages the use of PEG tube feeding.²²⁸ Costs to the facility are higher for residents without tubes (mainly due to staff time taken to feed the patient), while reimbursement is higher for patients with tubes (due in part to the cost of insertion and management of complications).

Back to Article Outline

Gastroenterology Workforce 

Physician Supply and Waiting Lists 

Studies of specialist supply and demand indicate that there will be a substantial shortfall in specialist hours provided by the current training model.²²⁹ In 2000, a combined task force of critical care and pulmonary specialists published the results of an analysis of the current and anticipated number of patients requiring pulmonary assessment and critical care, particularly admission to intensive care units, through 2030.²³⁰ Based on a detailed workforce assessment, they predicted that after 2007, demand for clinical services in these specialties would rapidly outstrip supply by 22% by 2020 and by 35% by 2030. The primary driving force was determined to be the aging of the population.

These numbers match those in a review of the gastroenterology workforce available in the United States in 1997, prepared as a report to the AGA Manpower and Training Committee in 1997. This report indicated that there was likely to be a significant shortfall in the gastroenterology workforce by 2010. A variety of forces were involved in creating the shortfall. These included a perceived oversupply of gastroenterologists by health maintenance organizations and other managed care organizations in the early 1990s²³¹ and agencies that identified specialist care as being expensive and less efficient than primary care. As a result, there was a 30% reduction in gastroenterology trainee positions in the United States between 1994 and 1997. By 1997, it was clear that a crisis was looming, and the decision to further decrease trainee positions was deferred and then abandoned. An additional factor identified as an issue in the 1997 AGA Manpower and Training Committee report was the looming retirement of the “baby boom” physician cohort expected to occur within 5 years (2003) and continuing for the next 15–20 years (to 2018). Records from the ABIM and other credentialing bodies indicated that ∼30% of the gastroenterology workforce in 1997 was within 5–10 years of retirement.

It is likely that a shortfall in gastroenterology workforce hours will result in delayed access and treatment. This is likely to increase adverse outcomes, particularly in patients who present with urgent but not emergent conditions that are not considered severe enough to warrant admission to the hospital. Examples would be chronic GI bleeding, complications of untreated malignancy, and chronic diarrhea, all of which have an increased risk of morbidity and mortality in older patients compared with younger individuals. Studies of other specialties that provide urgent assessment, such as cardiology, clearly show that delaying investigation due to long waiting lists increases mortality, morbidity, and risk of emergent hospitalization with longer hospital stays.²³² In this study of 381 patients, 91% of patients (mean age, 55 years) had an uneventful outcome. However, patients with a strongly positive treadmill test or positive stress imaging who waited longer than 3 weeks for assessment of coronary symptoms had increased risk of mortality, myocardial infarction, and urgent/emergent hospitalization with longer stay.

Gastroenterology Care by Generalists and Surgeons 

In 2000, a report of endoscopic services provided to a random sample of 5% of Medicare beneficiaries in Maryland by generalists²³³ indicated that generalists (internists, family practice) performed 7.7% of colonoscopies, 8.7% of upper endoscopies, 42.7% of flexible sigmoidoscopies, and 35.2% of rigid sigmoidoscopies. The procedures were usually of lower complexity, and patients had less severe morbidities. Other surveys estimate that the majority of colorectal cancer screening is performed by gastroenterologists (69.6%) and general surgeons (30.4%).²³⁴ This has implications for the type of patient referred to gastroenterologists practicing in an area with substantial generalist endoscopy availability. It is less clear how much generalist care impacts delivery of gastroenterology clinical care in the hospital setting, because internists and gastroenterologists share internal medicine coverage in many hospitals. Generalists will continue to see large numbers of patients in the outpatient setting with GI symptoms, and a substantial number will be treated without referral to a gastroenterologist.

Gastroenterology Care by Nonphysician Providers 

Projections of the workforce of nonphysician clinicians indicate that a substantial increase in these provider groups is likely to continue over the next several years. In 1998, Cooper et al²³⁵ estimated that the total number of nonphysician clinicians (nurse practitioners, physician assistants, nurse-midwives, nurse anesthetists, clinical nurse specialists, and other specialists such as chiropractors and podiatrists) would increase from 228,000 to 384,000. This was based on the rate of growth in 1998, which was averaging 20% per year. The greatest abundance of nonphysician clinicians trained was in states that already had large numbers of physicians. This is likely due to the effect of academic training centers positioned in large urban settings. The role of nonphysician clinicians in gastroenterology has been limited in the past to delivery of procedures such as sigmoidoscopy in a physician-supervised setting.²³⁶, ²³⁷, ²³⁸ More recently, an expanded role in patient education and clinical care has been proposed for advanced practice nurses²³⁹; however, most gastroenterology practices have not incorporated this model into their practice. It is also not clear whether this model would be more useful in a private practice setting or in an academic setting. Any future consideration of expanding the use of nonphysician clinicians in gastroenterology health care delivery would also need to address issues of specialty training and certification that have not been a component of nonphysician clinician training programs focused on primary care.

Back to Article Outline

Gastroenterology Education 

Gastroenterology Fellowship Programs 

Gastroenterology fellows will need training in the unique medical, social, and economic needs of the aging population. Such training has been recommended by the American Geriatrics Society in consultation with the Institute of Medicine and the Association of American Medical Colleges in their published guidelines in “Core Competencies for the Care of Older Patients.”²⁴⁰ The AGA Core Curriculum Committee has recognized this need and added a section concerning geriatric gastroenterology in 2003. The Accreditation Council for Graduate Medical Education has recently added geriatric gastroenterology under the heading “Specific Program Content” for the 2005 updated version.²⁴¹ Implementation of these guidelines needs to be standardized in gastroenterology programs.

Efforts are currently under way to increase the specific geriatric content of certifying and recertifying examinations in medical and nonmedical specialties, including gastroenterology. The goal of improving geriatric knowledge by specialists has been identified as essential by the Institute of Medicine, Department of Health and Human Services, and other groups that coordinate medical and surgical care in the United States and other countries. Gastroenterologists will be required to complete ABIM continuous professional development modules and take recertification examinations that contain more geriatric content. There is an urgent need for continuing medical education material to update practicing gastroenterologists who will face these examination requirements within the next 3–5 years. The Digestive Diseases Self-Education Program, which is used by many practicing gastroenterologists as a reference and board preparation course, does not contain any sections on geriatric gastroenterology. The most efficient way to improve continuing medical education in this area is the use of courses, such as the 2004 AGA postgraduate course that included data on geriatric gastroenterology issues, the continuous professional development review sessions at Digestive Disease Week, and other board review courses that focus on geriatric gastroenterology (Mount Sinai Hospital in 2000, University of Michigan in 2004), and inclusion into didactic material that is used by gastroenterologists (Digestive Diseases Self-Education Program, Medical Knowledge Self-Assessment Program).

Inpatient care 

In most fellowship programs, 80% of a gastroenterology fellow’s clinical training occurs during an inpatient setting (range, 60%–90%). Training will need to include specific recommendations for management of the complex geriatric inpatient, focusing on the issues described in previous sections. In many large academic medical centers and hospitals, residents and fellows are primarily responsible for inpatients with nominal oversight by faculty. It is essential, therefore, that training curricula include information on documentation of function, cognition, and appropriate use of ancillary services such as discharge planning and social work. Communication between health care providers will also be an important educational goal. Communication and appropriate use of other services are 2 of the Accreditation Council for Graduate Medical Education competencies that gastroenterology programs are now required to document in their fellows; however, many programs do not have a formal mechanism in place for documentation. Performing rounds with a geriatrician on selected days or with selected patients is a useful method of obtaining focused information useful for geriatric inpatient management.

Outpatient care 

Gastroenterology fellows will need to be educated in the unique aspects of geriatric outpatients. This will include differences between younger and elderly patients in the presentation and course of disease, response to interventions and medications, appropriate GI screening based on comorbidities and functional status, impact of dementia and depression on treatment, and balance of quality of life with appropriate interventions. At present, most outpatient clinics include a variety of patients of varying ages unless the clinic is focused on a condition that only affects young patients or a narrow age range. The potential to create geriatric gastroenterology clinics is present in centers that already have gastroenterology faculty with an interest in geriatrics or certification in geriatric medicine. Such clinics may be a powerful educational tool and may also provide a venue to obtain data concerning the logistics of seeing older patients in the outpatient setting.

Who Should Educate the Trainees? 

As gastroenterology educators take on the task of treating an increasingly aging population and training fellows, we will need to evaluate how the educators themselves are trained. Traditionally, trainees receive the majority of their training from gastroenterology faculty; however, many are not equipped to provide the geriatric-specific training outlined in this report. Revised curriculum material is needed to provide faculty with appropriate teaching materials. The utility and format of teaching material would need to be reviewed by gastroenterology program directors, perhaps during the annual gastroenterology program directors’ meeting. The model of physician-educators alone being involved in the education of fellows will likely change and will include greater participation by nonphysicians (eg, social workers, nurse care coordinators, and home visiting services personnel).

We suggest the following recommendations for training programs.

Any programs implementing level 2 training in geriatric gastroenterology would be strongly positioned as an attractive training center for compliance with certification and practice demands in the coming decade.

Back to Article Outline

Gastroenterological Research Questions and Needs 

Geriatric gastroenterology is a fertile field for research. Numerous questions exist about digestive disease in older patients and the best way to treat these patients. Following are various specific clinical research questions that should be addressed by the gastroenterology clinical research community.

Esophageal Function and Disease 

Colorectal Neoplasia 

Colorectal Cancer Screening 

Variceal Bleeding 

GI Immunity 

Drug Metabolism 

Endoscopic Procedures 

Using randomized trials that include larger numbers of geriatric patients (particularly age older than 85 years):

•Which drugs offer the best sedation options with the least drug interactions and side effects, that is, midazolam/fentanyl versus propofol anesthesia?

•What is the best use of routine oxygen supplementation during conscious sedation?

•What is the optimum degree of monitoring during conscious sedation?

PEG 

Outcomes Research 

Addressing many of the research questions listed in this report will require clinical research, particularly into outcomes of treatment in older patients. Currently, outcomes research focuses on inpatient care in conventional hospital settings or on ambulatory outpatients. Clinical research centers are not equipped to provide assistance with ADLs to older patients, because the staff is primarily focused on performing experiments or providing specific medical treatments. This raises the issue of whether a new type of research center needs to be developed to provide additional assistance appropriate for older patients in centers that anticipate a strong presence in geriatric outcomes research.

Documentation of outcomes by functional status, rather than age, also becomes crucial. There is considerable heterogeneity between individuals of advanced age, which means that results obtained in robust, ambulatory older patients of a certain age may be completely unusable in frail, older patients. Current database structures and recording systems are not designed to use function as a benchmark; rather, they usually use chronologic age.

Specific outcomes studies that should be conducted include the following:

In addition to the specific research questions presented, several more general research issues should be examined by the gastroenterology community. They are as follows.

Diarrhea and IBS 

Fecal Incontinence and Constipation 

NASH 

Pancreatic Disease 

New Diagnostic and Therapeutic Technologies 

Practice Management and Efficiency 

Important questions also exist in the practice management arena if geriatric patients are to be treated appropriately and efficiently. They include the following:

Back to Article Outline

Recommendations 

Following are a list of activities that the AGA could undertake that would help its clinician members better serve the needs of an aging population. Additional recommendations pertaining to gastroenterology training programs are found in the Gastroenterology Education section.

Back to Article Outline

References 

1. Keizer G. Life everlasting. The religious right and the right to die. Harper’s Magazine February 2005:52–61.
   • View In Article
2. Holt PR . Gastrointestinal diseases in the elderly . Curr Opin Clin Nutr Metab Care . 2003;6:41–48
   • View In Article
   • MEDLINE
   • CrossRef
3. American Gastroenterological Association . The burden of gastrointestinal diseases . VA: Lewin Group, Falls Church; 2001;
   • View In Article
4. Sandler RS, Everhart JE, Donowitz M, Adams E, Cronin K, Goodman C, et al. The burden of selected digestive diseases in the United States . Gastroenterology . 2002;122:1500–1511
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (128 KB)
   • CrossRef
5. Russo MW, Wei JT, Thiny MT, Gangarosa LM, Brown A, Ringel Y, et al. Digestive and liver diseases statistics, 2004 . Gastroenterology . 2004;126:1448–1453
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (89 KB)
   • CrossRef
6. Hall KE . Gastrointestinal disease in the geripause . In:  Eskin BA ,  Troen BR editor. The geripause: medical management during the late menopause . Boca Raton, FL: Parthenon Publishing Group Ltd; 2003;p. 175–184
   • View In Article
7. Miller RA . The biology of aging and longevity . In:  Hazzard WR ,  Blass JP ,  Halter JB ,  Ouslander JG ,  Tinetti ME editor. Principles of geriatric medicine and gerontology . 5th ed. New York: McGraw-Hill; 2003;p. 3–15
   • View In Article
8. Johnson SA , Cambier JC . Ageing, autoimmunity and arthritis (senescence of the B cell compartment—implications for humoral immunity) . Arthritis Res Ther . 2004;6:131–139
   • View In Article
9. Miller RA . Biochemical and genetic analyses of T cell aging in mice . Springer Semin Immunopathol . 2002;24:61–73
   • View In Article
   • MEDLINE
   • CrossRef
10. Effros RB . T cell replicative senescence (pleiotropic effects on human aging) . Ann N Y Acad Sci . 2004;1019:123–126
    • View In Article
    • MEDLINE
    • CrossRef
11. Small GW, Rabins PV, Barry PP, Buckholtz NS, DeKosky ST, Ferris SH, et al. Diagnosis and treatment of Alzheimer disease and related disorders. Consensus statement of the American Association for Geriatric Psychiatry, the Alzheimer’s Association, and the American Geriatrics Society . JAMA . 1997;278:1363–1371
    • View In Article
    • MEDLINE
12. Bloom BS , Chhatre S , Jayadevappa R . Cost effects of a specialized care center for people with Alzheimer’s disease . Am J Alzheimers Dis Other Demen . 2004;19:226–232
    • View In Article
    • MEDLINE
13. Hall KE . Effect of aging on gastrointestinal function . In:  Hazzard WR ,  Blass JP ,  Halter JB ,  Ouslander JG ,  Tinetti ME editor. Principles of geriatric medicine and gerontology . 5th ed. New York: McGraw-Hill; 2003;p. 593–600
    • View In Article
14. Firth M , Prather CM . Gastrointestinal motility problems in the elderly patient . Gastroenterology . 2002;122:1688–1700
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (139 KB)
    • CrossRef
15. Hall KE . Aging and neural control of the GI tract. II. Neural control of the aging gut: can an old dog learn new tricks? . Am J Physiol . 2002;283:G827–G832
    • View In Article
16. Wade PR , Cowen T . Neurodegeneration (a key factor in the ageing gut) . Neurogastroenterol Motil . 2001;16(Suppl 1):19–23
    • View In Article
    • CrossRef
17. Nydhal M , Andersson J , Sidenvall B , Gustafsson K , Fjellstrom C . Food and nutrient intake in a group of self-managing elderly Swedish women . J Nutr Health Aging . 2003;7:67–74
    • View In Article
    • MEDLINE
18. Westergren A , Unosson M , Ohlsson O , Lorefalt B , Hallberg IR . Eating difficulties, assisted eating and nutritional status in elderly (> or = 65 years) patients in hospital . Int J Nurs Stud . 2002;39:341–351
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (130 KB)
    • CrossRef
19. Mojet J , Heidema J , Christ-Hazelhof E . Effect of concentration on taste-taste interactions in foods for elderly and young subjects . Chem Senses . 2004;29:671–681
    • View In Article
    • MEDLINE
    • CrossRef
20. Mulligan C , Moreau K , Brandolini M , Livingstone B , Beaufrere B , Boirie Y . Alterations of sensory perceptions in healthy elderly subjects during fasting and refeeding. A pilot study . Gerontology . 2002;48:39–43
    • View In Article
    • MEDLINE
    • CrossRef
21. Chapman IM . Endocrinology of anorexia of aging . Best Pract Res Clin Endocrinol Metab . 2004;18:437–452
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (163 KB)
    • CrossRef
22. Horwitz BA , Blanton CA , McDonald RB . Physiologic determinants of the anorexia of aging (insights from animal studies) . Ann Rev Nutr . 2002;22:417–438
    • View In Article
23. Thomas P , Hazif-Thomas C , Clement JP . Influence of antidepressant therapies on weight and appetite in the elderly . J Nutr Health Aging . 2003;7:166–170
    • View In Article
    • MEDLINE
24. Nagler RM . Salivary glands and the aging process (mechanic aspects, health status and mechanical efficacy monitoring) . Biogerontology . 2004;5:223–233
    • View In Article
    • MEDLINE
    • CrossRef
25. Shaker R , Staff D . Esophageal disorders in the elderly . Gastroenterol Clin North Am . 2001;30:335–361
    • View In Article
    • Full Text
    • Full-Text PDF (2657 KB)
    • CrossRef
26. Schindler JS , Kelly JH . Swallowing disorders in the elderly . Laryngoscope . 2002;112:589–602
    • View In Article
    • MEDLINE
    • CrossRef
27. Frederick MG , Ott DJ , Grishaw EK , Gelfand DW , Chen MY . Functional abnormalities of the pharynx (a prospective analysis of radiographic abnormalities relative to age and symptoms) . AJR Am J Roentgenol . 1996;166:353–357
    • View In Article
    • MEDLINE
28. Leonard R , Kendall K , McKenzie S . UES opening and cricopharyngeal bar in nondysphagic elderly and nonelderly adults . Dysphagia . 2004;19:182–191
    • View In Article
    • MEDLINE
29. Kern M , Bardan E , Arndorfer R , Hofmann C , Ren J , Shaker R . Comparison of upper esophageal sphincter opening in healthy asymptomatic young and elderly volunteers . Ann Otol Rhinol Laryngol . 1999;108:982–989
    • View In Article
    • MEDLINE
30. Leonard R , Kendall KA , McKenzie S . Structural displacements affecting pharyngeal constriction in nondysphagic elderly and nonelderly adults . Dysphagia . 2004;19:133–141
    • View In Article
    • MEDLINE
31. Diamant NE . Physiology of the esophagus . In:  Sleisenger MH ,  Fordtran JS editor. Gastrointestinal disease: pathophysiology, diagnosis, management. Volume 1 . Philadelphia, PA: Saunders; 1994;p. 319
    • View In Article
32. Lingren S , Janzon L . Prevalence of swallowing complaints in clinical findings among 50 to 79 year old men and women . Dysphagia . 1991;6:187–192
    • View In Article
    • MEDLINE
    • CrossRef
33. Gorman RC , Morris JB , Kaiser LR . Esophageal disease in the elderly patient . Surg Clin North Am . 1994;74:93–112
    • View In Article
    • MEDLINE
34. Kim CH , Weaver AL , Hsu JJ , Rainwater L , Zinsmeister AR . Discriminate value of esophageal symptoms (a study of the initial clinical findings in 499 patients with dysphagia of various causes) . Mayo Clin Proc . 1993;68:948–954
    • View In Article
    • MEDLINE
35. Soergel KH , Zboralske FF , Amberg JR . Presbyesophagus (esophageal motility in nonagenerians) . J Clin Invest . 1964;43:1472–1479
    • View In Article
    • MEDLINE
    • CrossRef
36. Grishaw EK , Ott DJ , Frederick MG , Gelfand DW , Chen MY . Functional abnormalities of the esophagus (a prospective analysis of radiographic findings relative to age and symptoms) . AJR Am J Roentgenol . 1996;167:719–723
    • View In Article
    • MEDLINE
37. Khan TA , Shragge BW , Crispin JS , Lind JF . Esophageal motility in the elderly . Am J Dig Dis . 1977;22:1049–1054
    • View In Article
    • MEDLINE
    • CrossRef
38. Meciano Filho J , Carvalho VC , de Souza RR . Nerve loss in the myenteric plexus of the human esophagus in relation to age (a preliminary investigation) . Gerontology . 1995;41:18–21
    • View In Article
    • MEDLINE
    • CrossRef
39. Adamek RJ , Wegener M , Wienbeck M , Gielen B . Long-term esophageal manometry in healthy subjects. Evaluation of normal values and influence of age . Dig Dis Sci . 1994;39:2069–2073
    • View In Article
    • MEDLINE
    • CrossRef
40. Achem AC , Achem SR , Stark ME , DeVault KR . Failure of esophageal peristalsis in older patients (association with esophageal acid exposure) . Am J Gastroenterol . 2003;98:35–39
    • View In Article
    • MEDLINE
    • CrossRef
41. Smout AJ , Breedijk M , van der Zouw C , Akkermans LM . Physiologic gastroesophageal reflux in esophageal motor activity studied with a new system for 24-hr reading and automated analysis . Dig Dis Sci . 1989;34:372–378
    • View In Article
    • MEDLINE
    • CrossRef
42. Ren J, Shaker R, Kusano M, Podvrsan B, Metwally N, Dua KS, et al. Effect of aging on the secondary esophageal peristalsis (presbyesophagus revisited) . Am J Physiol . 1995;268:G772–G779
    • View In Article
    • MEDLINE
43. Nilsson M , Johnsen R , Ye W , Hveem K , Lagergren J . Prevalence of gastro-oesophageal reflux symptoms and the influence of age and sex . Scand J Gastroenterol . 2004;39:1040–1045
    • View In Article
    • MEDLINE
    • CrossRef
44. Locke GR , Talley NJ , Fett SL , Zinsmeister AR , Melton LJ . Prevalence and clinical spectrum of gastroesophageal reflux (a population-based study in Olmsted County, Minnesota) . Gastroenterology . 1997;112:1448–1456
    • View In Article
    • Abstract
    • Full-Text PDF (321 KB)
    • CrossRef
45. Johnson DA . Gastroesophageal reflux disease in the elderly—a prevalent and severe disease . Rev Gastroenterol Disord . 2004;4(Suppl 4):S16–S24
    • View In Article
46. Richter JE . Gastroesophageal reflux disease in the older patient (presentation, treatment, and complications) . Am J Gastroenterol . 2000;95:368–373
    • View In Article
    • MEDLINE
    • CrossRef
47. Hur C , Wittenberg E , Nishioka NS , Gazelle GS . Patient preferences for the management of high-grade dysplasia in Barrett’s esophagus . Dig Dis Sci . 2005;50:116–125
    • View In Article
    • MEDLINE
    • CrossRef
48. Rayner CK , MacIntosh CG , Chapman IM , Morley JE , Horowitz M . Effects of age on proximal gastric motor and sensory function . Scand J Gastroenterol . 2000;35:1041–1047
    • View In Article
    • MEDLINE
    • CrossRef
49. Linder JD , Wilcox CM . Acid peptic disease in the elderly . Gastroenterol Clin North Am . 2001;30:363–376
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (899 KB)
    • CrossRef
50. Feldman M , Cryer B , McArthur KE , Huet BA , Lee E . Effects of aging and gastritis on gastric acid in pepsin secretion in humans (a prospective study) . Gastroenterology . 1996;110:1043–1052
    • View In Article
    • Abstract
    • Full-Text PDF (121 KB)
    • CrossRef
51. Morihara M , Aoyagi N , Kaniwa N , Kojima S , Ogata H . Assessment of gastric acidity of Japanese subjects over the last 15 years . Biol Pharm Bull . 2001;24:313–315
    • View In Article
    • MEDLINE
    • CrossRef
52. Khalil T , Singh P , Fujimura M , Townsend CM , Greeley GH , Thompson JC . Effects of aging on gastric acid secretion, serum gastrin, antral gastrin content in rats . Dig Dis Sci . 1988;33:1544–1548
    • View In Article
    • MEDLINE
    • CrossRef
53. Jassel S , Ardill JES , Fillmore D , Bamford KB , O’Connor FA , Buchanan KD . The rise in circulating gastrin with age is due to increases in gastric autoimmunity and Helicobacter pylori infection . Q J Med . 1999;92:373–377
    • View In Article
54. Lee M , Feldman M . The aging stomach (implications for NSAID gastropathy) . Gut . 1997;41:425–426
    • View In Article
    • MEDLINE
    • CrossRef
55. Kim SW , Parekh D , Townsend CM , Thompson JC . Effects of aging on duodenal bicarbonate secretion . Ann Surg . 1990;212:332–338
    • View In Article
    • MEDLINE
    • CrossRef
56. Lee M , Feldman M . The aging stomach (implications for NSAID gastropathy) . Gut . 1997;1:425–426
    • View In Article
57. Hinsull SM . Effect of colloidal bismuth subcitrate on age-related gastric lesions in the rat . Gut . 1991;32:355–360
    • View In Article
    • MEDLINE
    • CrossRef
58. Newton JL , Jordan N , Pearson J , Williams GV , Allen A , James OF . The adherent gastric antral and duodenal mucus gel layer thins with advancing age in subjects infected with Helicobacter pylori . Gerontology . 2000;46:153–157
    • View In Article
    • MEDLINE
    • CrossRef
59. Fligiel SE , Relan NK , Dutta S , Tureaud J , Hatfield J , Majumdar AP . Aging diminishes gastric mucosal regeneration (relationship to tyrosine kinases) . Lab Invest . 1994;70:764–774
    • View In Article
    • MEDLINE
60. Relan ND , Fligiel SEG , Dutta S , Tureaud J , Chanhan DP , Majumdar APN . Induction of EGF-receptor tyrosine kinase during early reparative phase of gastric mucosa and effects of aging . Lab Invest . 1995;73:717–726
    • View In Article
    • MEDLINE
61. Xiao ZQ , Majumdar AP . Increased in vitro activation of EGFR by membrane-bound TGF-alpha from gastric and colonic mucosa of aged rats . Am J Physiol . 2001;281:G111–G116
    • View In Article
62. Li Y , Duckles SP . Effect of age on vascular content of calcitonin gene-related peptide and mesenteric vasodilator nerve activity in the rat . Eur J Pharmacol . 1993;236:373–378
    • View In Article
    • MEDLINE
    • CrossRef
63. Miyake H , Inaba N , Kato S , Takeuchi K . Increased susceptibility of rat gastric mucosa to ulcerogenic stimulation with aging (role of capsaicin-sensitive sensory neurons) . Dig Dis Sci . 1996;41:339–345
    • View In Article
    • MEDLINE
    • CrossRef
64. Crichton B , Green M . GP and patient perspectives on treatment with non-steroidal anti-inflammatory drugs for the treatment of pain . Curr Med Res Opin . 2002;18:92–96
    • View In Article
    • MEDLINE
    • CrossRef
65. Hunt RH, Harper S, Watson DJ, Yu C, Quan H, Lee M, et al. The gastrointestinal safety of the COX-2 selective inhibitor etoricoxib assessed by both endoscopy and analysis of upper gastrointestinal events . Am J Gastroenterol . 2003;98:1725–1733
    • View In Article
    • MEDLINE
    • CrossRef
66. Rahme E , Marentette MA , Kong SX , Lelorier J . Use of NSAIDs, COX-2 inhibitors, and acetaminophen and associated coprescriptions of gastroprotective agents in an elderly population . Arthritis Rheum . 2002;47:595–602
    • View In Article
    • MEDLINE
    • CrossRef
67. Delco F , Michetti P , Beglinger C , Fried M , Szues TD . Health care resource utilization and costs of NSAID-induced gastrointestinal toxicity. A population-based study in Switzerland . Digestion . 2004;69:10–19
    • View In Article
    • MEDLINE
    • CrossRef
68. Laine L , Wogen J , Yu H . Gastrointestinal health care resource utilization with chronic use of COX-2-specific inhibitors versus traditional NSAIDs . Gastroenterology . 2003;125:389–395
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (93 KB)
    • CrossRef
69. Goldstein JL , Huang B , Amer F , Christopoulos NG . Ulcer recurrence in high-risk patients receiving nonsteroidal anti-inflammatory drugs plus low-dose aspirin (results of a post HOC subanalysis) . Clin Ther . 2004;26:1637–1643
    • View In Article
    • Abstract
    • Full-Text PDF (525 KB)
    • CrossRef
70. Lohmander LS, McKeith D, Svensson O, Malmenas M, Bolin L, Kalla A, et al. A randomized, placebo-controlled, comparative trial of the gastrointestinal safety and efficacy of AZD3582 versus naproxen in osteoarthritis . Ann Rheum Dis . 2005;64:449–456
    • View In Article
    • MEDLINE
    • CrossRef
71. Chow LW , Gertsch P , Poon RT , Branicki FJ . Risk factors for rebleeding and death from peptic ulcer in the very elderly . Br J Surg . 1998;85:121–124
    • View In Article
    • MEDLINE
    • CrossRef
72. Lonstreth GF . Epidemiology and outcome of patients hospitalized with acute lower gastrointestinal hemorrhage (a population-based study) . Am J Gastroenterol . 1997;92:419–424
    • View In Article
    • MEDLINE
73. Bokhari M , Vernava AM , Ure T , Longo WE . Diverticular hemorrhage in the elderly—is it well tolerated? . Dis Colon Rectum . 1996;39:191–195
    • View In Article
    • MEDLINE
    • CrossRef
74. Raul F , Gosse F , Doffoel M , Darmenton P , Wessely JY . Age-related increase in brush-border enzyme activities along the small intestine . Gut . 1988;29:1557–1563
    • View In Article
    • MEDLINE
    • CrossRef
75. Jang I , Jung K , Cho J . Influence of age on duodenal brush border membrane and specific activities of brush border membrane enzymes in Wistar rats . Exp Anim . 2000;49:281–287
    • View In Article
    • MEDLINE
    • CrossRef
76. Saltzman JR , Kowdley KV , Perrone G , Russell RM . Changes in small-intestine permeability with aging . J Am Geriatr Soc . 1995;43:160–164
    • View In Article
    • MEDLINE
77. Hayashi H, Sato Y, Kanai S, Masuda M, Ohta M, Funakoshi A, et al. Lymphatic lipid transport is not impaired in ageing rat intestine . Mech Ageing Dev . 2000;113:219–225
    • View In Article
    • MEDLINE
    • CrossRef
78. Balogh G , Boland R , de Boland AR . 1,25(OH)(2)-vitamin D(3) affects the subcellular distribution of protein kinase C isoenzymes in rat duodenum (influence of aging) . J Cell Biochem . 2000;79:686–694
    • View In Article
    • MEDLINE
    • CrossRef
79. Jensen GL , McGee M , Binkley J . Nutrition in the elderly . Gastroenterol Clin North Am . 2001;30:313–334
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (1377 KB)
    • CrossRef
80. Vaquero MP . Magnesium and trace elements in the elderly (intake, status and recommendations) . J Nutr Health Aging . 2002;6:147–153
    • View In Article
    • MEDLINE
81. Gilani GS , Sepehr E . Protein digestibility and quality in products containing antinutritional factors are adversely affected by old age . J Nutr . 2003;133:220–225
    • View In Article
    • MEDLINE
82. Dangin M , Boirie Y , Guillet C , Beaufrere B . Influence of the protein digestion rate on protein turnover in young and elderly subjects . J Nutr . 2002;132:3228S–3233S
    • View In Article
    • MEDLINE
83. MacIntosh CG, Horowitz M, Verhagen MA, Smout AJ, Wishart J, Morris H, et al. Effect of small intestinal nutrient infusion on appetite, gastrointestinal hormone release, and gastric myoelectrical activity in young and older men . Am J Gastroenterol . 2001;96:997–1007
    • View In Article
    • MEDLINE
    • CrossRef
84. Holt PR , Yeh KY . Small intestine crypt cell proliferation rates are increased in senescent rats . J Gerontol . 1989;44:B9–B14
    • View In Article
    • MEDLINE
85. Graff J , Brinch K , Madsen JL . Gastrointestinal mean transit times in young and middle-aged healthy subjects . Clin Physiol . 2001;21:253–259
    • View In Article
    • MEDLINE
    • CrossRef
86. Feher E , Penzes L . Density of substance P, vasoactive intestinal polypeptide and somatostatin-containing nerve fibers in the ageing small intestine of the rats . Gerontology . 1987;33:341–348
    • View In Article
    • MEDLINE
    • CrossRef
87. Belai A , Burnstock G . Distribution and colocalization of nitric oxide synthase and calretinin in myenteric neurons of developing, aging and Crohn’s disease human small intestine . Dig Dis Sci . 1999;44:1579–1587
    • View In Article
    • MEDLINE
    • CrossRef
88. El-Salhy M , Sandstrom O , Holmlund F . Age-induced changes in the enteric nervous system in the mouse . Mech Ageing Dev . 1999;107:93–103
    • View In Article
    • MEDLINE
    • CrossRef
89. Smits GJ , Lefebvre RA . Influence of aging on gastric emptying of liquids, small intestine transit, and fecal output in rats . Experimental Gerontology . 1996;31:589–596
    • View In Article
    • MEDLINE
    • CrossRef
90. Wade PR . Age-related changes in the enteric nervous system . Am J Physiol . 2002;283:G489–G495
    • View In Article
91. Mattson MP . Molecular biology of the aging nervous system . In:  Duckett S ,  De La Torre JC editor. Pathology of the aging human nervous system . New York, NY: Oxford University Press; 2001;p. 16–41
    • View In Article
92. Cowen T , Johnson RJ , Soubeyre V , Santer RM . Restricted diet rescues rat enteric motor neurones from age related cell death . Gut . 2000;47:653–660
    • View In Article
    • MEDLINE
    • CrossRef
93. Parlesak A , Klein B , Schecher K , Bode JC , Bode C . Prevalence of bacterial overgrowth and its association with nutrition intake in nonhospitalized older adults . J Am Geriatr Soc . 2003;51:768–773
    • View In Article
    • MEDLINE
    • CrossRef
94. Camilleri M , Lee JS , Viramontes B , Bharucha AE , Tangalos EG . Insights into the pathophysiology and mechanisms of constipation, irritable bowel syndrome, and diverticulosis in older people . J Am Geriatr Soc . 2000;48:1142–1150
    • View In Article
    • MEDLINE
95. Meier R, Beglinger C, Dederding JP, Meyer-Wyss B, Fumagalli M, Rowedder A, et al. Influence of age, gender, hormonal status and smoking habits on colonic transient time . Neurogastroenterol Motil . 1995;7:235–238
    • View In Article
    • MEDLINE
    • CrossRef
96. Gomes OA , deSouza RR , Liberti EA . A preliminary investigation of the effects of aging on the nerve cell number in the myenteric ganglia of the human colon . Gerontology . 1997;43:210–217
    • View In Article
    • MEDLINE
    • CrossRef
97. Takahashi T , Qoubaitary A , Owyang C , Wiley JW . Decreased expression of nitric oxide synthase in the colonic myenteric plexus of aged rats . Brain Res . 2000;883:15–21
    • View In Article
    • MEDLINE
    • CrossRef
98. Roberts D , Gelperin D , Wiley JW . Evidence for age-associated reduction in acetylcholine release and smooth muscle response in the rat colon . Am J Physiol . 1994;267:G515–G522
    • View In Article
    • MEDLINE
99. Hall KE, Sheng HC, Srinivasan S, Spitsbergen JM, Tuttle JB, Steers WD, et al. Treatment of aged rat sensory neurons in short-term, serum-free culture with nerve growth factor reverses the effect of aging on neurite outgrowth, calcium currents, and neuronal survival . Brain Res . 2001;888:128–137
    • View In Article
    • MEDLINE
    • CrossRef
100. Keirnan JA , Heinicke EA . Sennosides do not kill myenteric neurons in the colon of the rat or mouse . Neuroscience . 1989;30:837–842
     • View In Article
     • MEDLINE
     • CrossRef
101. Nadal SR , Calore EE , Manzione CR , Puga FR , Perez NM . Effects of long-term administration of Senna occidentalis seeds in the large bowel of rats . Pathol Res Pract . 2003;199:733–737
     • View In Article
     • MEDLINE
     • CrossRef
102. Freeman SR , McNally PR . Diverticulitis . Med Clin North Am . 1993;77:1149–1167
     • View In Article
     • MEDLINE
103. Petersen TI , Kissmeyer-Nielsen P , Laurberg S , Christensen H . Impaired wound healing but unaltered colonic healing with increasing age (an experimental study in rats) . Eur Surg Res . 1995;27:250–257
     • View In Article
     • MEDLINE
     • CrossRef
104. Murakami H, Iwane S, Munakata A, Nakaji S, Sugawara K, Tsuchida S, et al. Changes in intraluminal pressure in rat large intestines with aging and effects of dietary fiber . Dig Dis Sci . 2001;46:1247–1254
     • View In Article
     • MEDLINE
     • CrossRef
105. Ferzoco LB , Raptopoulos V , Silen W . Acute diverticulitis . N Engl J Med . 1998;338:1521–1526
     • View In Article
     • MEDLINE
     • CrossRef
106. Shih YC, Barghout VE, Sandler RS, Jhingran P, Sasane M, Cook S, et al. Resource utilization associated with irritable bowel syndrome in the United States 1987-1997 . Dig Dis Sci . 2002;47:1705–1715
     • View In Article
     • MEDLINE
     • CrossRef
107. Sandler RS , Stewart WF , Liberman JN , Ricci JA , Zorich NL . Abdominal pain, bloating, and diarrhea in the United States (prevalence and impact) . Dig Dis Sci . 2000;45:1166–1171
     • View In Article
     • MEDLINE
     • CrossRef
108. Ehrenpreis ED . Irritable bowel syndrome. 10% to 20% of older adults have symptoms consistent with diagnosis . Geriatrics . 2005;60:25–28
     • View In Article
     • MEDLINE
109. Miller DP , Alfredson T , Cook SF , Sands BE , Walker AM . Incidence of colonic ischemia, hospitalized complications of constipation, and bowel surgery in relation to use of alosetron hydrochloride . Am J Gastroenterol . 2003;98:1117–1122
     • View In Article
     • MEDLINE
     • CrossRef
110. Kim HJ, Camilleri M, McKensie S, Lempke MB, Burton DD, Thomforde GM, et al. A randomized controlled trial of a probiotic, VSL#3, on gut transit and symptoms in diarrhoea-predominant irritable bowel syndrome . Aliment Pharmacol Ther . 2003;17:895–904
     • View In Article
     • MEDLINE
     • CrossRef
111. Kosek M , Bern C , Guerrant RL . The global burden of diarrhoeal disease, as estimated from studies published between 1992 and 2000 . Bull World Health Organ . 2003;81:197–204
     • View In Article
     • MEDLINE
112. Hoffmann JC , Zeitz M . Small bowel disease in the elderly (diarrhoea and malabsorbtion) . Best Pract Res Clin Gastroenterol . 2002;16:17–36
     • View In Article
     • Abstract
     • Full-Text PDF (190 KB)
     • CrossRef
113. Broens RM , Pennickx FM . Relation between anal electrosensitivity and rectal filling sensation and the influence of age . Dis Colon Rectum . 2005;48:127–133
     • View In Article
     • MEDLINE
     • CrossRef
114. De Lillo AR , Rose S . Functional bowel disorders in the geriatric patient (constipation, fecal impaction, and fecal incontinence) . Am J Gastroenterol . 2000;95:901–905
     • View In Article
     • MEDLINE
     • CrossRef
115. Read NW , Celik AF , Katsinelos P . Constipation and incontinence in the elderly . J Clin Gastroenterol . 1995;20:61–70
     • View In Article
     • MEDLINE
     • CrossRef
116. Arnaud MJ . Mild dehydration (a risk factor of constipation?) . Eur J Clin Nutr . 2003;57:S88–S95
     • View In Article
     • CrossRef
117. Tytgat GN, Heading RC, Muller-Lissner S, Kamm MA, Scholmerich J, Berstad A, et al. Contemporary understanding and management of reflux and constipation in the general population and pregnancy (a consensus meeting) . Aliment Pharmacol Ther . 2003;18:291–301
     • View In Article
     • MEDLINE
     • CrossRef
118. Cooper ZR , Rose S . Fecal incontinence (a clinical approach) . Mt Sinai J Med . 2000;67:96–105
     • View In Article
     • MEDLINE
119. Schiller LR . Constipation and fecal incontinence in the elderly . Gastroenterol Clin North Am . 2001;30:497–515
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (1120 KB)
     • CrossRef
120. Cheetham M , Brazzelli M , Norton C , Glazener CMA . Drug treatment for faecal incontinence in adults . Cochrane Database Syst Rev . 2003;3:CD002116
     • View In Article
121. Jorge JMN , Wexner SD . Etiology and management of fecal incontinence . Dis Colon Rectum . 1993;36:77–97
     • View In Article
     • MEDLINE
     • CrossRef
122. Ryhammer AM , Laurberg S , Sorensen FH . Effects of age on anal function in normal women . Int J Colorectal Dis . 1997;12:225–229
     • View In Article
     • MEDLINE
     • CrossRef
123. Papachrysostomou M , Pye SD , Wild SR , Smith AN . Significance of the thickness of the anal sphincters with age and its relevance in faecal incontinence . Scand J Gastroenterol . 1994;29:710–714
     • View In Article
     • MEDLINE
     • CrossRef
124. Morris AR , Ho MT , Lapsley H , Walsh J , Gonski P , Moore KH . Costs of managing urinary and faecal incontinence in a sub-acute care facility (a “bottom-up” approach) . Neurourol Urodyn . 2005;24:56–62
     • View In Article
     • MEDLINE
     • CrossRef
125. Sun WM , Read NW , Verlinden M . Effects of loperamide oxide on gastrointestinal transit time and anorectal function in patients with chronic diarrhoea and faecal incontinence . Scand J Gastroenterol . 1997;32:34–38
     • View In Article
     • MEDLINE
     • CrossRef
126. Chassagne P, Jego A, Gloc P, Capet C, Trivalle C, Doucet J, et al. Does treatment of constipation improve faecal incontinence in institutionalized elderly patients? . Age Aging . 2000;29:159–164
     • View In Article
127. Carapeti EA , Kamm MA , Nicholls RJ , Phillips RKS . Randomized, controlled trial of topical phenylephrine for fecal incontinence in patients after ileoanal pouch construction . Dis Colon Rectum . 2000;43:1059–1063
     • View In Article
     • MEDLINE
     • CrossRef
128. Cheetham MJ , Kamm MA , Phillips RKS . Topical phenylephrine increases anal canal resting pressure in patients with faecal incontinence . Gut . 2001;48:356–359
     • View In Article
     • MEDLINE
     • CrossRef
129. Madiba TE , Baig MK , Wexner SD . Surgical management of rectal prolapse . Arch Surg . 2005;140:63–73
     • View In Article
     • MEDLINE
     • CrossRef
130. Xiao ZQ , Jaszewski R , Majumdar AP . Aging enhances G(1) phase in the colonic mucosa of rats . Mech Ageing Dev . 2000;116:1–14
     • View In Article
     • MEDLINE
     • CrossRef
131. Nensey YM , Arlow FL , Majumdar AP . Aging. Increased responsiveness of colorectal mucosa to carcinogen stimulation and protective role of folic acid . Dig Dis Sci . 1995;40:396–401
     • View In Article
     • MEDLINE
     • CrossRef
132. Malecka-Panas E , Relan NK , Majumdar AP . Increased activation of EGF-receptor tyrosine kinase by EGF and TGF-α in colonic mucosa of aged rats . J Gerontol A Biol Sci Med Sci . 1996;51:B60–B65
     • View In Article
     • MEDLINE
133. Lee HM , Greeley GH , Englander EW . Effects of aging on expression of genes involved in regulation of proliferation and apoptosis in the colonic epithelium . Mech Ageing Dev . 2000;115:139–155
     • View In Article
     • MEDLINE
     • CrossRef
134. Basdanis G, Papadopoulos VN, Michalopoulos A, Fahantidis E, Apostolidis S, Berovalis P, et al. Colorectal cancer in patients over 70 years of age (determinants of outcome) . Techn Coloproctol . 2004;8(Suppl 1):s112–s115
     • View In Article
135. Kirchgatterer A, Steiner P, Hubner D, Fritz E, Aschl G, Preisinger J, et al. Colorectal cancer in geriatric patients (endoscopic diagnosis and surgical treatment) . World J Gastroenterol . 2005;11:315–318
     • View In Article
     • MEDLINE
136. Ho P , Law WL , Chan SC , Lam CK , Chu KW . Functional outcome following low anterior resection with total mesorectal excision in the elderly . Int J Colorectal Dis . 2003;18:230–233
     • View In Article
     • MEDLINE
137. Sonnenberg A , Delco F , Inadomi JM . Cost-effectiveness of colonoscopy in screening for colorectal cancer . Ann Intern Med . 2000;133:573–584
     • View In Article
     • MEDLINE
138. US Preventive Services Task Force screening for CRC (recommendation and rationale) . Ann Intern Med . 2002;137:129–131
     • View In Article
139. Harewood GC , Lieberman DA . Colonoscopy practice patterns since introduction of Medicare coverage for average-risk screening . Clin Gastroenterol Hepatol . 2004;2:72–77
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (112 KB)
     • CrossRef
140. Imperiale TF , Wagner DR , Lin CY , Larkin GN , Rogge JD , Ransohoff DF . Risk of advanced proximal neoplasms in asymptomatic adults according to the distal colorectal findings . N Engl J Med . 2000;343:169–174
     • View In Article
     • MEDLINE
     • CrossRef
141. Koketsu S , Watanabe T , Tada T , Kanazawa T , Ueda E , Nagawa H . Sporadic colorectal cancer in elderly people . Hepatogastroenterology . 2003;50:1749–1752
     • View In Article
     • MEDLINE
142. Okamoto M, Kawabe T, Yamagji Y, Kato J, Ikenoue T, Togo G, et al. Flat-type early colorectal cancer preferentially develops in right-sided colon in older patients . Dis Colon Rectum . 2005;48:101–107
     • View In Article
     • MEDLINE
     • CrossRef
143. Miller K , Waye JD . Colorectal polyps in the elderly (what should be done?) . Drugs Aging . 2002;19:393–404
     • View In Article
     • MEDLINE
     • CrossRef
144. Miller K , Waye JD . Approach to colon polyps in the elderly . Am J Gastroenterol . 2000;95:1147–1151
     • View In Article
     • MEDLINE
     • CrossRef
145. Sardinha TC, Nogueras JJ, Ehrenpreis ED, Zeitman D, Estevez V, Weiss EG, et al. Colonoscopy in octogenarians (a review of 428 cases) . Int J Colorectal Dis . 1999;14:172–176
     • View In Article
     • MEDLINE
     • CrossRef
146. Hixson LJ , Fennerty MB , Sampliner RE , McGee DL , Garewal H . Two-year incidence of colon adenomas developing after tandem colonoscopy . Am J Gastroenterol . 1994;89:687–691
     • View In Article
     • MEDLINE
147. Winkleman BJ , Matthews DE , Wiebke EA . Colorectal cancer screening at a Veterans Affairs hospital . Am J Surg . 2003;186:468–471
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (37 KB)
     • CrossRef
148. AGA Manpower and Training Committee Report on Manpower Issues . 1997;
     • View In Article
149. Marshall JR , Fay D , Lance P . Potential costs of flexible sigmoidoscopy-based colorectal cancer screening . Gastroenterology . 1996;111:1411–1417
     • View In Article
     • Abstract
     • Full-Text PDF (322 KB)
     • CrossRef
150. Pickhardt PJ , Nugent PA , Mysliwiec PA , Choi JR , Schindler WR . Location of adenomas missed by optical colonoscopy . Ann Intern Med . 2004;141:352–359
     • View In Article
151. Van Dam J, Cotton P, Johnson CD, McFarland BG, Pineau BC, Provenzale D, et al. AGA future trends report (CT colonography) . Gastroenterology . 2004;127:970–984
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (162 KB)
     • CrossRef
152. Coady-Fariborzain L , Angel LP , Procaccino JA . Perforated colon secondary to virtual colonoscopy (report of a case) . Dis Colon Rectum . 2004;47:1247–1249
     • View In Article
     • MEDLINE
     • CrossRef
153. Kamar M, Portnoy O, Bar-Dayan A, Amitai M, Munz Y, Ayalon A, et al. Actual colonic perforation in virtual colonoscopy (report of a case) . Dis Colon Rectum . 2004;47:1242–1246
     • View In Article
     • MEDLINE
     • CrossRef
154. Pineau BC, Paskett ED, Chen GJ, Espeland MA, Phillips K, Han JP, et al. Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps . [see comment] Gastroenterology . 2003;125:304–310
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (113 KB)
     • CrossRef
155. Lieberman DA , Weiss DG , Bond JH , Ahnen DJ , Garewal H , Chejfec G . Use of colonoscopy to screen asymptomatic adults for colorectal cancer . N Engl J Med . 2000;343:162–168
     • View In Article
     • MEDLINE
     • CrossRef
156. Baron JA, Cole BF, Sandler RS, Haile RW, Ahnen D, Bresalier R, et al. A randomized trial of aspirin to prevent colorectal adenomas . N Engl J Med . 2003;348:891–899
     • View In Article
     • CrossRef
157. Sandler RS, Halabi S, Baron JA, Budinger S, Paskett E, Keresztes R, et al. A randomized trial of aspirin to prevent colorectal adenomas in patients with previous colorectal cancer . N Engl J Med . 2003;348:883–890
     • View In Article
     • CrossRef
158. Chao A, Thun MJ, Connell CJ, McCullough ML, Jacobs EJ, Flanders WD, et al. Meat consumption and risk of colorectal cancer . JAMA . 2005;293:172–182
     • View In Article
     • CrossRef
159. Imperiale TF , Ransohoff DF , Itzkowitz SH , Turnbull BA , Ross ME  Colorectal Cancer Study Group . Fecal DNA versus fecal occult blood for colorectal-cancer screening in an average-risk population . [see comment] N Engl J Med . 2004;351:2704–2714
     • View In Article
     • CrossRef
160. Wynne HA , Cope LH , Mutch E , Rawlins MD , Woodhouse KW , James OF . The effect of age upon liver volume and apparent liver blood flow in healthy man . Hepatology . 1989;9:297–301
     • View In Article
     • MEDLINE
     • CrossRef
161. Handler JA , Genell CA , Goldstein RS . Hepatobiliary function in senescent male Sprague-Dawley rats . Hepatology . 1994;19:1496–1503
     • View In Article
     • MEDLINE
     • CrossRef
162. Liu Y, Guyton KZ, Gorospe M, Xu Q, Kokkonen GC, Mock YD, et al. Age-related decline in mitogen activated protein kinase activity in epidermal growth factor-stimulated rat hepatocytes . J Biochem . 1996;74:3604–3607
     • View In Article
163. Krupczak-Hollis K , Wang X , Dennewitz MB , Costa RH . Growth hormone stimulates proliferation of old-aged regenerating liver through forkhead box m1b . Hepatology . 2003;38:1552–1562
     • View In Article
     • MEDLINE
     • CrossRef
164. Ledda-Columbano GM , Pibiri M , Cossu C , Molotzu F , Locker J , Columbano A . Aging does not reduce the hepatocyte proliferative response of mice to the primary mitogen TCPOBOP . Hepatology . 2004;40:981–988
     • View In Article
     • MEDLINE
     • CrossRef
165. Jang I , Chae K , Cho J . Effects of age and strain on small intestinal and hepatic antioxidant defense enzymes in Wistar and Fisher 344 rats . Mech Ageing Dev . 2001;122:561–570
     • View In Article
     • MEDLINE
     • CrossRef
166. Anand BS . Drug treatment of the complications of cirrhosis in the older adult . Drugs Aging . 2001;18:575–585
     • View In Article
     • MEDLINE
     • CrossRef
167. De Franchis R , Banares R , Silvain C . Emergency endoscopy strategies for improved outcomes . Scand J Gastroenterol . 1998;S226:25–36
     • View In Article
168. Stein LB , Dabezies MA , Silverman M , Brozena SC . Fatal torsade de pointes occurring in a patient receiving intravenous vasopressin and nitroglycerin . J Clin Gastroenterol . 1992;15:171–174
     • View In Article
     • MEDLINE
169. Siegel D , Lopez J , Meier J . Use of cholesterol-lowering medications in the United States from 1991 to 1997 . Am J Med . 2000;108:496–499
     • View In Article
     • Full Text
     • Full-Text PDF (81 KB)
     • CrossRef
170. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults . Executive summary of the third report of the National Cholesterol Education Program (NCEP) (Adult Treatment Panel III) . JAMA . 2001;285:2486–2497
     • View In Article
     • MEDLINE
     • CrossRef
171. Ko DT , Mamdani M , Alter DA . Lipid-lowering therapy with statins in high-risk elderly patients. The treatment paradox . JAMA . 2004;291:1864–1870
     • View In Article
     • CrossRef
172. Pazzi P, Putinati S, Limone G, Barbieri D, Trevisani L, Lupi L, et al. The effect of age and sex on gallbladder motor dynamics. An echographic study . Radiol Med . 1989;77:365–368
     • View In Article
     • MEDLINE
173. Wedmann B , Schmidt G , Wegener M , Coenen C , Ricken D , Althoff J . Effects of age and gender on fat-induced gallbladder contraction and gastric emptying of a caloric liquid meal (a sonographic study) . Am J Gastroenterol . 1991;86:1765–1770
     • View In Article
     • MEDLINE
174. Siou GP , Belai A , Burnstock G . Age-related changes in galanin- and calretinin-immunoreactive nerves of guinea-pig gallbladder . Neuroreport . 1992;3:990–992
     • View In Article
     • MEDLINE
     • CrossRef
175. Khalil T, Walker JP, Wiener I, Fagan CJ, Townsend CM, Greeley GH, et al. Effect of aging on gallbladder contraction and release of cholecystokinin-33 in humans . Surgery . 1985;98:423–429
     • View In Article
     • MEDLINE
176. Mercado MA, Chan C, Orozco H, Hinojosa CA, Tinajero JC, Santamaria Galeotti LN, et al. Bile duct reconstruction after iatrogenic injury in the elderly . Ann Hepatol . 2004;3:160–162
     • View In Article
     • MEDLINE
177. Majumdar AP , Jaszewski R , Dubick MA . Effect of aging on gastrointestinal tract and the pancreas . Proc Soc Exp Biol Med . 1997;215:134–144
     • View In Article
     • MEDLINE
178. Laugier R , Bernard JP , Berthezene P , Dupuy P . Changes in pancreatic exocrine secretion with age (pancreatic exocrine secretion does not decrease in the elderly) . Digestion . 1991;50:202–211
     • View In Article
     • MEDLINE
179. Vellas B, Balas D, Moreau J, Bouisson M, Senegas-Balas F, Guidet M, et al. Exocrine pancreatic secretion in the elderly . Int J Pancreatol . 1988;3:497–502
     • View In Article
     • MEDLINE
180. Glaser J , Stienecker K . Does aging influence pancreatic response in the ultrasound secretin test by impairing hydrokinetic exocrine function or sphincter of Oddi motor function? . Dig Liver Dis . 2000;32:25–28
     • View In Article
     • Abstract
     • Full-Text PDF (2000 KB)
     • CrossRef
181. Poston GJ , Saydjari R , Lawrence JP , Chung D , Townsend CM , Thompson JC . Aging and the trophic effects of cholecystokinin, bombesin and pentagastrin on the rat pancreas . Pancreas . 1991;6:407–411
     • View In Article
     • MEDLINE
     • CrossRef
182. Greenberg RE , Holt PR . Influence of aging upon pancreatic digestive enzymes . Dig Dis Sci . 1986;31:970–977
     • View In Article
     • MEDLINE
     • CrossRef
183. Khalid A , Whitcomb DC . Conservative treatment of chronic pancreatitis . Eur J Gastroenterol Hepatol . 2002;14:943–949
     • View In Article
     • MEDLINE
     • CrossRef
184. Andren-Sandberg A , Hoem D , Gislason H . Pain management in chronic pancreatitis . Eur J Gastroenterol Hepatol . 2002;14:957–970
     • View In Article
     • MEDLINE
     • CrossRef
185. Bathe OF, Caldera H, Hamilton KL, Franceschi D, Sleeman D, Livingstone AS, et al. Diminished benefit from resection of cancer of the head of the pancreas in patients of advanced age . J Surg Oncol . 2001;77:115–122
     • View In Article
     • MEDLINE
     • CrossRef
186. Schmucker DL , Thoreux K , Owen RL . Aging impairs intestinal immunity . Mech Ageing Dev . 2001;122:1397–1411
     • View In Article
     • MEDLINE
     • CrossRef
187. Fleming AL , Field EH , Tolaymat N , Cowdery JS . Age influences recovery of systemic and mucosal immune responses following acute depletion of CD4 T cells . Clin Immunol Immunopathol . 1993;69:285–291
     • View In Article
     • MEDLINE
     • CrossRef
188. Schmucker DL , Owen RL , Outenreath R , Thoreux K . Basis for the age-related decline in intestinal mucosal immunity . Clin Dev Immunol . 2003;10:167–172
     • View In Article
     • MEDLINE
     • CrossRef
189. Dunlop SP , Jenkins D , Spiller RC . Age-related decline in rectal mucosal lymphocytes and mast cells . Eur J Gastroenterol Hepatol . 2004;16:1011–1015
     • View In Article
     • MEDLINE
     • CrossRef
190. Beharka AA , Paiva S , Leka LS , Ribaya-Mercado JD , Russell RM , Nibkin Meydani S . Effect of age on the gastrointestinal-associated mucosal immune response of humans . J Gerontol Series A Biol Sci Med Sci . 2001;56:B218–B223
     • View In Article
191. Mounts AW , Holman RC , Clarke MJ , Bresee JS , Glass RI . Trends in hospitalizations associated with gastroenteritis among adults in the United States, 1979-1995 . Epidemiol Infect . 1999;123:1–8
     • View In Article
     • MEDLINE
     • CrossRef
192. Bressler R , Bahl J . Principles of drug therapy for the elderly patient . Mayo Clin Proc . 2003;78:1564–1577
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (119 KB)
     • CrossRef
193. Guengerich FP . Human cytochrome P450 enzymes . In:  Ortiz de Montellano PR editors. Cytochrome P450: structure, mechanism and biochemistry . New York, NY: Plenum; 1995;p. 473–535
     • View In Article
194. Hunt CM , Westerkam WR , Stave GM , Wilson JA . Hepatic cytochrome p-4503A (CYP3A) activity in the elderly . Mech Ageing Dev . 1992;64:189–199
     • View In Article
     • MEDLINE
     • CrossRef
195. Wilkinson GR . Cytochrome P4503A (CYP3A) metabolism (prediction of in vivo activity in humans) . J Pharmacokinet Biopharm . 1996;24:475–490
     • View In Article
     • MEDLINE
     • CrossRef
196. Skett P , Tyson C , Guillouzo A , Maier P . Report on the international workshop on the use of human in vitro liver preparations to study drug metabolism in drug development . Biochem Pharmacol . 1995;50:280–285
     • View In Article
     • MEDLINE
     • CrossRef
197. Ravdin LD , Mattis PJ , Lachs MS . Assessment of cognition in primary care (neuropsychological evaluation of the geriatric patient) . Geriatrics . 2004;59:37–40 42,44
     • View In Article
     • MEDLINE
198. Folstein MF , Folstein SE , McHugh PR . Mini-Mental State (a practical method for grading the cognitive state of patients for the clinician) . J Psychiatr Res . 1975;12:196–198
     • View In Article
199. Borson S , Scanlan JM , Chen P , Ganguli M . The Mini-Cog as a screen for dementia (validation in a population-based sample) . J Am Geriatr Soc . 2003;51:1451–1454
     • View In Article
     • MEDLINE
     • CrossRef
200. Gostlin LO . Informed consent, cultural sensitivity, and respect for persons . (editorial) JAMA . 1995;274:844–845
     • View In Article
     • MEDLINE
201. Bynum JP , Rabins PV , Weller W , Niefeld M , Anderson GF , Wu AW . The relationship between a dementia diagnosis, chronic illness, medical expenditures, and hospital use . J Am Geriatr Soc . 2003;52:187–194
     • View In Article
     • MEDLINE
     • CrossRef
202. Lebowitz BD, Pearson JL, Schneider LS, Reynolds CF, Alexopoulos GS, Bruce ML, et al. Diagnosis and treatment of depression in late life. Consensus statement update. Consensus Development Conference . JAMA . 1997;278:1186–1190
     • View In Article
     • MEDLINE
203. Stommel M , Kurtz ME , Kurtz JC , Given CW , Given BA . A longitudinal analysis of the course of depressive symptomatology in geriatric patients with cancer of the breast, colon, lung, or prostate . Health Psychol . 2004;23:564–573
     • View In Article
     • MEDLINE
     • CrossRef
204. Sheikh JI , Yesavage JA . Geriatric Depression Scale (recent evidence and development of a shorter version) . Clin Gerontol . 1986;5:165–172
     • View In Article
     • CrossRef
205. El Solh AA , Brewer T , Okada M , Bashir O , Gough M . Indicators of recurrent hospitalization for pneumonia in the elderly . J Am Geriatr Soc . 2004;52:2010–2015
     • View In Article
     • MEDLINE
     • CrossRef
206. Adams RJ , Smith BJ , Ruffin RE . Impact of the physician’s participatory style in asthma outcomes and patient satisfaction . Ann Allergy Asthma Immunol . 2001;86:263–271
     • View In Article
     • Abstract
     • Full-Text PDF (185 KB)
     • CrossRef
207. CMS-1429FC. #612. Revisions to Payment Policies Under the Physician Fee Schedule for Calendar Year 2005. http://www.cms.hhs.gov/medicare/hcpcs/.
     • View In Article
208. Munoz E , Greenberg R , Faust G , Goldstein JD , Bank S , Wise L . Gastroenterology, diagnosis-related groups, and age . J Clin Gastroenterol . 1989;11:421–429
     • View In Article
     • MEDLINE
     • CrossRef
209. Grau L , Kovner C . Comorbidity, age, and hospital use among elderly Medicare patients . J Aging Health . 1991;3:352–367
     • View In Article
     • MEDLINE
     • CrossRef
210. Beasley JW, Hankey TH, Erickson R, Stange KC, Mundt M, Elliott M, et al. How many problems do family physicians manage at each encounter? . A WReN study. Ann Fam Med . 2004;2:405–410
     • View In Article
211. Starfield B , Lemke KW , Bernhardt T , Foldes SS , Forrest CB , Weiner JP . Comorbidity (implications for the importance of primary care in ‘case’ management) . Ann Fam Med . 2003;1:8–14
     • View In Article
     • MEDLINE
     • CrossRef
212. Cherry DK , Burt CW , Woodwell DA . National Ambulatory Medical Care Survey (2001 summary) . Adv Data . 2003;337:1–44
     • View In Article
213. Prajapati DN, Saeian K, Binion DG, Staff DM, Kim JP, Massey BT, et al. Volume and yield of screening colonoscopy at a tertiary medical center after change in Medicare reimbursement . Am J Gastroenterol . 2003;98:194–199
     • View In Article
     • MEDLINE
     • CrossRef
214. Thompson AM , Wright DJ , Murray W , Ritchie GL , Burton HD , Stonebridge PA . Analysis of 153 deaths after upper gastrointestinal endoscopy (room for improvement?) . Surg Endosc . 2004;18:22–25
     • View In Article
     • CrossRef
215. Bell GD , Bown S , Morden A , Coady T , Logan RF . Prevention of hypoxemia during upper gastrointestinal endoscopy by means of oxygen via nasal cannulae . Lancet . 1987;1:1022–1024
     • View In Article
     • MEDLINE
216. de la Mora G , Marcon NE . Endoscopy in the elderly patient . Best Pract Res Clin Gastroenterol . 2001;15:999–1012
     • View In Article
     • Abstract
     • Full-Text PDF (157 KB)
     • CrossRef
217. Arrowsmith JB , Gerstman BB , Fleischer DE , Benjamin SB . Results from the American Society for Gastrointestinal Endoscopy/U.S. Food and Drug Administration collaborative study on complication rates and drug use during gastrointestinal endoscopy . Gastrointest Endosc . 1991;37:421–427
     • View In Article
     • Abstract
     • Full-Text PDF (5892 KB)
     • CrossRef
218. Ure T , Dehghan K , Vernava AM , Longo WE , Andrus CA , Daniel GL . Colonoscopy in the elderly. Low risk, high yield . Surg Endosc . 1995;9:505–508
     • View In Article
     • MEDLINE
219. Ristikankare M , Hartikainen J , Heikkinen M , Janatuinen E , Julkunen R . The effects of gender and age on the colonoscopic examination . J Clin Gastroenterol . 2001;32:69–75
     • View In Article
     • MEDLINE
     • CrossRef
220. Lukens FJ , Loeb DS , Machicao VI , Achem SR , Picco MF . Colonoscopy in octogenarians (a prospective outpatient study) . Am J Gastroenterol . 2002;97:1722–1725
     • View In Article
     • MEDLINE
     • CrossRef
221. Rex DK , Imperiale TF , Portish V . Patients willing to try colonoscopy without sedation (associated clinical factors and results of a randomized controlled trial) . Gastrointest Endosc . 1999;49:554–559
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (46 KB)
     • CrossRef
222. Heymann TD , Chopra K , Nunn E , Coulter L , Westaby D , Murray-Lyon IM . Bowel preparation at home (prospective study of adverse effects in elderly people) . BMJ . 1996;313:727–728
     • View In Article
     • MEDLINE
     • CrossRef
223. Gangi S , Saidi F , Patel K , Johnstone B , Jaeger J , Shine D . Cardiovascular complications after GI endoscopy (occurrence and risks in a large hospital system) . Gastrointest Endosc . 2004;60:679–685
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (102 KB)
     • CrossRef
224. Seinela L , Pehkonen E , Laasanen T , Ahvenainen J . Bowel preparation for colonoscopy in very old patients (a randomized prospective trial comparing oral sodium phosphate and polyethylene glycol electrolyte lavage solution) . Scand J Gastroenterol . 2003;38:216–220
     • View In Article
     • MEDLINE
     • CrossRef
225. Affronti J . Biliary disease in the elderly . Clin Geriatr Med . 1999;15:571–578
     • View In Article
     • MEDLINE
226. Pothuri B, Montemarano M, Gerardi M, Shike M, Ben-Porat L, Sabbatini P, et al. Percutaneous endoscopic gastrostomy tube placement in patients with malignant bowel obstruction due to ovarian carcinoma . Gynecol Oncol . 2005;96:330–334
     • View In Article
     • MEDLINE
     • CrossRef
227. Callahan CM, Haag KM, Weinberger M, Tierney WM, Buchanan NN, Stump TE, et al. Outcomes of percutaneous endoscopic gastrostomy among older adults in a community setting . J Am Geriatr Soc . 2000;48:1048–1054
     • View In Article
     • MEDLINE
228. Mitchell SL , Buchanan JL , Littlehale S , Hamel MB . Tube-feeding versus hand-feeding nursing home residents with advanced dementia (a cost comparison) . J Am Med Dir Assoc . 2004;5(2 Suppl):S22–S29
     • View In Article
     • MEDLINE
     • CrossRef
229. Buck ST , Trauba V , Christensen RG . Minnesota physician workforce analysis (rural supply and demand) . Minn Med . 2004;87:40–43
     • View In Article
     • MEDLINE
230. Angus DC , Kelley MA , Schmitz RJ , White A , Popovich J . Committee on Manpower for Pulmonary and Critical Care Societies (COMPACCS) . JAMA . 2000;284:2762–2770
     • View In Article
     • MEDLINE
     • CrossRef
231. Meyer GS , Jacoby I , Krakauer H , Powell DW , Aurand J , McCardle P . Gastroenterology workforce modeling . JAMA . 1996;276:689–694
     • View In Article
     • MEDLINE
232. Rosanio S, Tocchi M, Cutler D, Uretsky BF, Stouffer GA, deFilippi CR, et al. Queuing for coronary angiography during severe supply-demand mismatch in a US public hospital (analysis of a waiting list registry) . JAMA . 1999;282:145–152
     • View In Article
     • MEDLINE
     • CrossRef
233. Meyer GS , Cheng EY , Elting J . Differences between generalists and specialists in characteristics of patients receiving gastrointestinal procedures . J Gen Intern Med . 2000;15:188–194
     • View In Article
     • MEDLINE
     • CrossRef
234. Brown ML , Klabunde CN , Mysliwiec P . Current capacity for endoscopic colorectal cancer screening in the United States (data from the National Cancer Institute Survey of Colorectal Cancer Screening Practices) . Am J Med . 2003;115:129–133
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (68 KB)
     • CrossRef
235. Cooper RA , Laud P , Dietrich CL . Current and projected workforce of nonphysician clinicians . JAMA . 1998;280:788–794
     • View In Article
     • MEDLINE
     • CrossRef
236. Schoenfeld P . Flexible sigmoidoscopy by paramedical personnel . J Clin Gastroenterol . 1999;28:110–116
     • View In Article
     • MEDLINE
     • CrossRef
237. Hillier A . The advanced practice nurse in gastroenterology. Identifying and comparing care interactions of nurse practitioners and clinical nurse specialists . Gastroenterol Nurs . 2001;24:239–245
     • View In Article
     • MEDLINE
     • CrossRef
238. Cash BD , Schoenfeld PS , Ransohoff DF . Licensure, use, and training of paramedical personnel to perform screening flexible sigmoidoscopy . Gastrointest Endosc . 1999;49:163–169
     • View In Article
     • Abstract
     • Full Text
     • Full-Text PDF (45 KB)
     • CrossRef
239. Manning M . The advanced practice nurse in gastroenterology serving as patient educator . Gastroenterol Nurs . 2004;27:220–225
     • View In Article
     • MEDLINE
     • CrossRef
240. The Education Writing Group of the American Geriatrics Society . Core competencies for the care of older patients (recommendations of the American Geriatrics Society) . Acad Med . 2000;75:252–255
     • View In Article
     • MEDLINE
241. ACGME Program Requirements for Fellowship Education in Gastroenterology. Effective date 7/2005. http://www.acgme.org/acWebsite/RRC_140/140_prIndex.asp.
     • View In Article
242. Ahern M , Imperial J , Lam S . Impact of a designated hepatology nurse on the clinical course and quality of life of patients treated with rebetron therapy for chronic hepatitis C . Gastroenterology Nursing . 2004;27:149–155
     • View In Article