December 2020

Volume 159Issue 6p1995-2250, e1-e14

Covering the Cover

  • Covering the Cover

    • Andrew T. Chan,
    • Christopher S. Williams
    Published online: November 06, 2020
    A cohort study compared intestinal microbiota in children with celiac disease and healthy children.


  • Colorectal Cancer Screening in the Novel Coronavirus Disease-2019 Era

    • Evelien Dekker,
    • Han-Mo Chiu,
    • Iris Lansdorp-Vogelaar,
    • on COVID-19 of the WEO Colorectal Cancer Screening Committee
    Published online: September 20, 2020
    “All major population-based screening programs will shortly grind to an unseemly halt.”
  • Monitoring Fecal Microbiota Transplantation Practice in a Rapidly Evolving Health and Regulatory Environment

    • Colleen R. Kelly,
    • Loren A. Laine,
    • Gary D. Wu
    Published online: August 22, 2020
    Fecal microbiota transplantation (FMT) has demonstrated high efficacy in recurrent Clostridioides difficile infections (CDI).1 However, it remains an investigational therapy that may be used by practitioners without an investigational new drug (IND) application to treat CDI not responding to standard therapies under a policy of enforcement discretion by the U.S. Food and Drug Administration (FDA).2 This regulatory policy is driven, in part, by concerns that available safety data for FMT are inadequate, although there have been few serious short-term adverse events or infection transmissions reported in the literature to date.
  • Moving Toward Impact: An Introduction to Implementation Science for Gastroenterologists and Hepatologists

    • Shari S. Rogal,
    • Byron J. Powell,
    • Matthew Chinman,
    • On behalf of the Gastroenterology and Hepatology Implementation Research Group
    Published online: September 17, 2020
    Implementation science (IS) is the “scientific study of methods to promote the systematic uptake of research findings and other evidence-based practices into routine practice, and, hence, to improve the quality and effectiveness of health services and care.”1 IS is a burgeoning field with tremendous potential to positively impact gastroenterology and hepatology. Thus, this commentary aims to introduce gastroenterologists to the nomenclature, frameworks, and research designs of IS using relevant clinical examples.

Meeting Summary

  • Defining Endpoints and Biomarkers in Inflammatory Bowel Disease: Moving the Needle Through Clinical Trial Design

    • Maria T. Abreu,
    • William J. Sandborn
    • and the IOIBD Defining Endpoints and Biomarkers in Inflammatory Bowel Disease Writing Group
    Published online: September 19, 2020
    Open Access
    Discovery and development of new drugs for the treatment of inflammatory bowel disease (IBD) has intensified significantly within the past decade. However, numerous hurdles affect the pace and efficiency with which new drugs are developed. On March 20, 2019 the International Organization for the Study of Inflammatory Bowel Disease (IOIBD) held a meeting entitled “Defining Endpoints and Biomarkers in Inflammatory Bowel Disease: Moving the Needle Through Clinical Trial Design” in Miami, Florida. In addition to IOIBD members and IBD specialists, representatives from both industry and regulatory agencies were invited to speak and provide expert opinions and perspectives on the current landscape, factors influencing the evolution of IBD clinical trial design and endpoints, and potential novel approaches that may advance the field.
    Online ExtraAdditional Online Content Available

Mentoring, Education, and Training Corner

  • Navigating the Human Gut Microbiome: Pathway to Success from Lessons Learned

    • Jun Miyoshi,
    • Mrinalini C. Rao,
    • Eugene B. Chang
    Published online: September 07, 2020
    The rapid evolution of cultivation-independent, multi-omic technologies has increased our appreciation of the complexity, diversity, and vital roles of the human gut microbiome in health and disease, taking it from the realm of dark mystery to one of enlightened fascination. We now know that, in health, the gut microbiome is important for the proper functioning of both digestive and extraintestinal organ systems. It has also become apparent that perturbations of the gut that disrupt critical interactions between host and gut microbes, namely, gut dysbiosis, can cause or promote disease.


  • Could a Small Population of Epithelial Cells Get “Tuft” With Crohn’s Disease?

    • Michael J. Rosen
    Published online: September 30, 2020
    Although the rare intestinal tuft cell, distinguished by its “tuft” of apical microvilli, accounts for <1% of intestinal epithelial cells, it has a profound role in sensing luminal contents to influence the mucosal immune response.1 Several parallel discoveries over the past 4 years have demonstrated that tuft cells are a key epithelial intermediary for orchestrating a mucosal type 2 immune response to eukaryotic parasites, including helminths and protists.2–4 In response to parasites, tufts cells initiate a positive feedback loop by secreting IL-25, which activates group 2 innate lymphoid cells (ILC2s) to produce the type 2 cytokine IL-13 (Figure 1A).

Clinical Challenges and Images in GI

  • A “Nonemergent” Case of Air Under the Diaphragm

    • Dhairya A. Lakhani,
    • Yousaf Hadi,
    • Melinda Smith
    Published online: April 29, 2020
    Question: A 70-year-old man presented to the emergency department with nausea and abdominal pain for 1 week. He reported that he had presented to multiple emergency rooms over the course of the last week and had been prescribed antiemetics to no avail.
  • Generalized Gingival Hyperplasia and Rectorrhagia in a 13-Year-Old Boy

    • Alexandre Courtet,
    • Julie Lemale,
    • Maria Clotilde Carra
    Published online: May 03, 2020
    Question: A 13-year-old boy of Arab origin was referred to the Department of Periodontology with a chief complaint of generalized bleeding gums for 3 years, which had an impact on his daily quality of life. The young patient did not report any particular symptoms other than a chronic fatigue that hampered his sport activities. The patient’s mother mentioned 2 episodes of perianal abscess that were surgically drained at the age of 6 months and 1 year and few episodes of rectorrhagia during childhood.
  • Colitis in a Rheumatologic Patient

    • Jacob Lui,
    • Jaime de la Fuente,
    • Magnus Halland
    Published online: May 03, 2020
    Question: A 46-year-old woman with a medical history of psoriatic arthritis, antiphospholipid syndrome, and previous pulmonary embolism on warfarin was admitted with a 2-week history of progressive right upper quadrant pain, frequent nonbloody diarrhea, tenesmus, and nonbloody emesis. Her immunosuppressant therapy included certolizumab for the past 5 years and leflunomide for the past 17 months. She denied use of other medications. She has no personal or family history of inflammatory bowel disease.

Electronic Clinical Challenges and Images in GI

  • Segmental Polyposis

    • Sarah Wu,
    • Jing Yang,
    • Jerrold R. Turner
    Published online: April 20, 2020
    Question: A 41-year-old woman underwent sigmoid colectomy. As occurs commonly, the specimen was received in the surgical pathology laboratory with no information other than the patient’s name, medical record number, and “sigmoid.” The surgeon could not be contacted. On opening the colon, a well-defined region with innumerable small polyps was identified (Figure A). Within this region was an ulcer (arrow) and associated stricture. Proximal and distal mucosal margins were uninvolved and had normal folds.
    Online Only
  • Melena in Neonates: Endoscopic Surprise

    • Aathira Ravindranath,
    • Moinak Sen Sarma,
    • Dimple Jain
    Published online: April 17, 2020
    Question: Baby DR, born to a term multipara, was delivered in the fields with uneventful recovery. At postgestation week 3, he presented with daily melena without overt hematemesis or systemic features and required multiple packed red blood cell transfusions. The infant was exclusively breast fed with poor weight gain. He was received at postgestation week 8 with hemoglobin 5.3 g/dL, microcytic hypochromic smear, and an absolute eosinophil count of 3401/mm3. Platelet count, prothrombin time, activated partial thromboplastin time, total serum protein, and albumin were normal.
    Online Only
  • A Rare Finding of a Common Presentation

    • George Salem,
    • Donald J. Kastens
    Published online: April 17, 2020
    Question: An 87-year-old-woman brought to the emergency department by her family for further evaluation of progressive dysphagia. Her family members describe progressive dysphagia for solids and liquids for the past 2 years, with a 20-pound weight loss in the last 2-month period. This was attributed to lack of oral intake. Vital signs were within normal limits. Mild kyphosis was noted. On auscultation, she had coarse crackles with poor air entry sounds over the bases bilaterally, with soft late expiratory wheeze best heard over both apices.
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  • Unusual Esophageal Polyps in Advanced Cirrhosis

    • Edgar Afecto,
    • David Afonso João,
    • Adélia Rodrigues
    Published online: April 23, 2020
    Question: A 55-year-old man was referred to our emergency department for odynophagia after an accidental caustic fluid ingestion. Physical examination was unremarkable. He had past history of cirrhosis (alcohol and hepatitis C as etiologic factors, currently Child-Pugh score C), diagnosed in the previous year. At the time of cirrhosis diagnosis, an extensive intrahepatic and extrahepatic portal vein thrombosis was identified by ultrasound and confirmed by computed tomography. Although there was high clinical suspicion of malignant thrombosis, no solid hepatic nodules were detected (by ultrasound examination, computed tomography scan, or magnetic resonance imaging) and alpha-fetoprotein levels were normal (3.6 ng/mL).
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  • Terminal Ileum Thickening and Mucosal Ulcers in a Boy With Neurofibromatosis Type 1

    • Giulia Angelino,
    • Paola Francalanci,
    • Renato Tambucci
    Published online: April 23, 2020
    Question: A 19-year-old man presented with diarrhea, abdominal pain and distension, vomiting, and weight loss. Medical history was positive for neurofibromatosis type 1 (NF1), with a heterozygous mutation in the NF1 gene (c.33707G>A). Clinical examination showed poor nutritional status, diffuse café-au-lait spots, abdominal tenderness, and a palpable mass. Blood tests were normal; in particular, no anemia or inflammation indexes were detected. Upper endoscopy showed hiatal hernia and mild gastritis, and ileocolonoscopy revealed diffuse and deep ulcerations in the terminal ileum, surrounded by erythematous mucosa (Figure A), with a normal-appearing colon.
    Online Only
  • An Unusual Cause of Cholecystitis

    • Tao-Qian Tang,
    • Ming-Hung Hsu,
    • Wen-Lun Wang
    Published online: April 24, 2020
    Question: A 62-year-old man without a significant past medical or surgical history presented with a 1-month history of intermittent dull right upper quadrant pain, which sometimes occur postprandially and was sometimes associated with mild nausea. He denied any fever, trauma, tarry stool, jaundice, tea-colored urine, or pain radiation. He took an over-the-counter proton pump inhibitor of his own accord, but the symptoms persisted. He was subsequently referred to our hospital. Physical examination revealed mild tenderness over right upper quadrant of abdomen, with positive Murphy’s sign.
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Practical Teaching Case

  • A Curious Case of Confusion in a Patient With Cirrhosis

    • Amrit K. Kamboj,
    • Jerry Yung-Lun Chin,
    • Robert C. Huebert
    Published online: April 15, 2020
    Question: A 40-year-old woman presented with dyspnea and bilateral lower extremity edema. She had a past history of decompensated alcohol-related cirrhosis complicated by small esophageal varices, spontaneous bacterial peritonitis, hepatic encephalopathy on lactulose and rifaximin, and small volume ascites on furosemide and spironolactone. She had severe alcohol use disorder but had been abstinent for 6 months and was recently listed for liver transplantation.

Original Research

Continuing Medical Education (CME)/MOC Activities

Brief Communications

  • Impact of Obesity on Outcomes of Patients With Coronavirus Disease 2019 in the United States: A Multicenter Electronic Health Records Network Study

    • Shailendra Singh,
    • Mohammad Bilal,
    • Haig Pakhchanian,
    • Rahul Raiker,
    • Gursimran S. Kochhar,
    • Christopher C. Thompson
    Published online: August 20, 2020
    During the 2009 H1N1 influenza A virus pandemic, obesity was significantly associated with increased risk for hospitalization and mortality.1 In 2020, the coronavirus disease 2019 (COVID-19) pandemic has a higher estimated case fatality rate.2 It has hit the United States at a time when obesity has also reached epidemic status, with the prevalence of obesity increasing from 30.5% to 42.4% and of severe obesity increasing from 4.7% to 9.2% over the past decade.3 Comorbidities associated with obesity are widely recognized risk factors for poor COVID-19 outcomes4; however, larger population-based data evaluating obesity as an independent risk factor continue to be sparse.
    Online ExtraAdditional Online Content Available
  • Prevalence, Risk Factors, and Outcomes of Hospitalized Patients With Coronavirus Disease 2019 Presenting as Acute Pancreatitis

    • Sumant Inamdar,
    • Petros C. Benias,
    • Yan Liu,
    • ...
    • Sanjaya K. Satapathy,
    • Arvind J. Trindade
    • and the Northwell COVID-19 Research Consortium
    Published online: August 26, 2020
    The novel coronavirus disease 2019 (COVID-19) has caused a global pandemic. Although most patients present with respiratory symptoms, gastrointestinal (GI) symptoms have also been reported in up to 25% of patients.1 Some case reports have shown acute pancreatitis as the initial presentation in patients with COVID-19.2–4 As islet cells of the pancreas contain ACE2 receptor proteins, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can bind to these receptors and cause pancreatic injury.
    Online ExtraAdditional Online Content Available
  • Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Patients With Inflammatory Bowel Disease Under Biologic Treatment

    • Lorenzo Norsa,
    • Paola Cosimo,
    • Amedeo Indriolo,
    • Naire Sansotta,
    • Lorenzo D’Antiga,
    • Annapaola Callegaro
    Published online: August 26, 2020
    The Lombardy region of Italy was the second epicenter of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection after China, with Bergamo province being the most affected area. The Hospital Papa Giovanni XXIII, the tertiary referral center for inflammatory bowel disease (IBD) in the whole province, was reconverted into a coronavirus disease 2019 (COVID-19) point of care, with up to 500 beds dedicated to patients with COVID-19 and more than 1,500 admissions for severe COVID-19 during the early phase of the local epidemic.
    Online ExtraAdditional Online Content Available
  • Epoxygenase-Derived Epoxyeicosatrienoic Acid Mediators Are Associated With Nonalcoholic Fatty Liver Disease, Nonalcoholic Steatohepatitis, and Fibrosis

    • Ashwini Arvind,
    • Stephanie A. Osganian,
    • Julia A. Sjoquist,
    • Kathleen E. Corey,
    • Tracey G. Simon
    Published online: August 04, 2020
    Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the United States and is projected to become the leading indication for liver transplantation by 2030. Among patients with NAFLD, nearly 25% develop nonalcoholic steatohepatitis (NASH), which accelerates progression to fibrosis and cirrhosis. However, reliable biomarkers capable of identifying NASH are lacking. Discovering such biomarkers may facilitate drug development and help identify high-risk patients who are most likely to benefit from therapy.
    Online ExtraAdditional Online Content Available
  • Low Risk of Advanced Neoplasms for up to 20 Years After Negative Colonoscopy Result: Potential for Personalized Follow-up Screening Intervals

    • Thomas Heisser,
    • Feng Guo,
    • Tobias Niedermaier,
    • Bernd Holleczek,
    • Michael Hoffmeister,
    • Hermann Brenner
    Published online: August 06, 2020
    Open Access
    For the general population at average risk, major US and European guidelines recommend 10-year colonoscopy intervals to screen for colorectal cancer (CRC).1 However, evidence on intervals beyond 10 years is very sparse, and little is known on the potential of risk-adapted, personalized follow-up screening examinations. The objective of our study was to investigate the prevalence of advanced colorectal neoplasms (ADNs) (advanced adenomas or cancers) after longer colonoscopy intervals and the possible role of easy-to-collect factors for risk stratification.
    Online ExtraAdditional Online Content Available
  • Early-Onset Esophageal Adenocarcinoma Presents With Advanced-Stage Disease But Has Improved Survival Compared With Older Individuals

    • Jennifer M. Kolb,
    • Samuel Han,
    • Frank I. Scott,
    • ...
    • Patrick Hosokawa,
    • Sachin Wani
    • on behalf of the Early Onset Esophageal Adenocarcinoma Study Group
    Published online: August 07, 2020
    Esophageal adenocarcinoma (EAC) incidence and mortality is increasing in the United States.1 In spite of implementing screening and surveillance programs for the precursor lesion Barrett’s esophagus and greater recognition of this highly lethal cancer, most patients present with late-stage disease associated with a poor prognosis.
    Online ExtraAdditional Online Content Available
  • Monoallelic NTHL1 Loss-of-Function Variants and Risk of Polyposis and Colorectal Cancer

    • Fadwa A. Elsayed,
    • Judith E. Grolleman,
    • Abiramy Ragunathan,
    • ...
    • Daniel D. Buchanan,
    • Tom van Wezel,
    • Richarda M. de Voer
    Published online: August 25, 2020
    Open Access
    The endonuclease III-like protein 1, encoded by NTHL1, is a bifunctional glycosylase involved in base-excision repair (BER) that recognizes and removes oxidized pyrimidines.1 Similar to biallelic loss-of-function (LoF) variants in MUTYH,2 biallelic LoF variants in NTHL1 predispose to colorectal polyps and colorectal cancer (CRC).3 Recently, a multitumor phenotype was observed in individuals diagnosed with NTHL1 deficiency.4 Carriers of monoallelic pathogenic variants in MUTYH have an increased, albeit small, risk of CRC.
    Online ExtraAdditional Online Content Available

Selected Summaries


  • Noninferiority or Nonsuperiority?

    • Maarten te Groen,
    • Nathan den Broeder,
    • Frank Hoentjen
    Published online: May 16, 2020
    We read with great interest the article by Rivéro-Sanchez et al.1 The authors reported on high-definition white-light endoscopy compared to dye-based chromoendoscopy in patients with Lynch syndrome. With the wide-spread implementation of high-definition white-light endoscopy, the necessity of chromoendoscopy has been debated.2 We much appreciate this contribution to the understanding of the optimal surveillance strategy for Lynch syndrome, and encourage the use of a noninferiority design to compare performance between available endoscopic techniques.
  • Positive Fecal Immunochemical Test or Cologuard in the Era of the Novel Coronavirus Disease-2019 Pandemic

    • Patrick E. Young,
    • Micheal Tadros,
    • Sheena Mago
    Published online: May 22, 2020
    We have encountered a few patients with positive fecal immunochemical test (FIT) and multitarget DNA/FIT tests (MT-DNA/FIT) in the midst of the novel coronavirus disease-2019 (COVID-19) pandemic that have required us to have detailed discussions with our patients and balance the pros and cons of proceeding with colonoscopy now verses postponing it for possibly >6 weeks, until the end of this crisis.


  • Cover 1

    Published in issue: December 2020
  • Editorial Board

    Published in issue: December 2020
  • Table of Contents

    Published in issue: December 2020
  • Elsewhere in The AGA Journals

    Published in issue: December 2020
  • Information for Authors and Readers

    Published in issue: December 2020
    Gastroenterology is the premiere journal in the field of gastrointestinal disease and is led by an internationally renowned board of editors. As the official journal of the AGA Institute, Gastroenterology delivers up-to-date and authoritative coverage of both basic and clinical gastroenterology and hepatology. Regular features include research and perspectives by leading authorities, reports on the latest technologies for diagnosing and treating digestive diseases, images illustrating important clinical findings, reviews of scholarly media, medical news, meeting summaries, video abstracts, and monthly podcasts.