Bleeding and Perforation After Outpatient Colonoscopy and Their Risk Factors in Usual Clinical Practice

Published:September 16, 2008DOI:

      Background & Aims

      The most widely quoted complication rates for colonoscopy are from case series performed by expert endoscopists. Our objectives were to evaluate the rates of bleeding, perforation, and death associated with outpatient colonoscopy and their risk factors in a population-based study.


      We identified all individuals 50 to 75 years old who underwent an outpatient colonoscopy during April 1, 2002, to March 31, 2003, in British Columbia, Alberta, Ontario, and Nova Scotia, Canada. Using administrative data, we identified all individuals who were admitted to hospital with bleeding or perforation within 30 days following the colonoscopy in each province. We calculated the pooled rates of bleeding and perforation from the 4 provinces. In Ontario, we abstracted the hospital charts of all deaths that occurred within 30 days following the procedure. We used generalized estimating equations models to evaluate factors associated with bleeding and perforation.


      We identified 97,091 persons who had an outpatient colonoscopy. The pooled rates of colonoscopy-related bleeding and perforation were 1.64/1000 and 0.85/1000, respectively. The death rate was 0.074/1000 or approximately 1/14,000. Older age, male sex, having a polypectomy, and having the colonoscopy performed by a low-volume endoscopist were associated with increased odds of bleeding or perforation.


      Although colonoscopy has established benefits for the detection of colorectal cancer and adenomatous polyps, the procedure is associated with risks of serious complications, including death. Older age, male sex, having a polypectomy, and having the procedure done by a low-volume endoscopist were independently associated with colonoscopy-related bleeding and perforation.

      Abbreviations used in this paper:

      CIHI (Canadian Institute for Health Information)
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        • Jemal A.
        • Siegel R.
        • Ward E.
        • et al.
        Cancer statistics, 2008.
        CA Cancer J Clin. 2008; 58: 71-96
        • Canadian Cancer Society/National Cancer Institute of Canada
        Canadian cancer statistics 2008.
        2008 (Toronto, Canada)
        • US Preventive Services Task Force
        Screening for colorectal cancer: Recommendation and rationale.
        Ann Intern Med. 2002; 137: 129-131
        • Levin B.
        • Lieberman D.A.
        • McFarland B.
        • et al.
        Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology.
        Gastroenterology. 2008; 134: 1570-1595
        • Leddin D.
        • Hunt R.
        • Champion M.
        • et al.
        Canadian Association of Gastroenterology and the Canadian Digestive Health Foundation: Guidelines on colon cancer screening.
        Can J Gastroenterol. 2004; 18: 93-99
        • Rex D.K.
        • Bond J.H.
        • Winawer S.
        • et al.
        Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the US Multi-Society Task Force on Colorectal Cancer.
        Am J Gastroenterol. 2002; 97: 1296-1308
        • Levin T.R.
        • Zhao W.
        • Conell C.
        • et al.
        Complications of colonoscopy in an integrated health care delivery system.
        Ann Intern Med. 2006; 145: 880-886
        • Department of Health and Human Services
        The international classification of diseases, 9th revision, clinical modification.
        3rd ed. Government Printing Office, Washington, DC1989
        • World Health Organization
        ICD-10: international statistical classification of diseases and health related problems, 10th revision.
        World Health Organization, Geneva1992
        • Deyo R.A.
        • Cherkin D.C.
        • Ciol M.A.
        Adapting a clinical co-morbidity index for use with ICD-9-CM administrative databases.
        J Clin Epidemiol. 1992; 45: 613-619
        • Sundararajan V.
        • Henderson T.
        • Perry C.
        • et al.
        New ICD-10 version of the Charlson comorbidity index predicted in-hospital mortality.
        J Clin Epidemiol. 2004; 57: 1288-1294
        • Bressler B.
        • Paszat L.F.
        • Chen Z.
        • et al.
        Rates of new or missed colorectal cancers after colonoscopy and their risk factors: a population-based analysis.
        Gastroenterology. 2007; 132: 96-102
        • Stukel T.A.
        • Demidenko E.
        • Dykes J.
        • et al.
        Two-stage methods for the analysis of pooled data.
        Stat Med. 2001; 20: 2115-2130
        • Viiala C.H.
        • Zimmerman M.
        • Cullen D.J.E.
        • et al.
        Complication rates of colonoscopy in an Australian teaching hospital environment.
        Intern Med J. 2003; 33: 355-359
        • Anderson M.L.
        • Pasha T.M.
        • Leighton J.A.
        Endoscopic perforation of the colon: lessons from a 10-year study.
        Am J Gastroenterol. 2000; 95: 3418-3422
        • Rathberger S.W.
        • Wick T.M.
        Colonoscopy completion and complication rates in a community gastroenterology practice.
        Gastrointest Endosc. 2006; 64: 556-562
        • Regula J.
        • Rupinski M.
        • Kraszewska E.
        • et al.
        Colonoscopy in colorectal-cancer screening for detection of advanced neoplasia.
        N Engl J Med. 2006; 355: 1863-1872
        • Gatto N.M.
        • Frucht H.
        • Sundararajan V.
        • et al.
        Risk of perforation after colonoscopy and sigmoidoscopy: a population-based study.
        J Natl Cancer Inst. 2003; 95: 230-236
        • Nelson D.B.
        • McQuaid K.R.
        • Bond J.H.
        • et al.
        Procedural success and complications of large-scale screening colonoscopy.
        Gastrointest Endosc. 2002; 55: 307-314
        • Rex D.K.
        Have we defined best colonoscopic polypectomy practice in the United States?.
        Clin Gastroenterol Hepatol. 2007; 5: 674-677

      Linked Article

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          Recent guidelines representing multiple societies promote colonoscopy as the optimal test for colorectal cancer (CRC) screening.1 Although no direct evidence (ie, randomized, controlled trials) exist to prove the efficacy of colonoscopy to reduce mortality from CRC, substantial indirect evidence has been published supporting a general belief that this strategy will decrease cancer incidence and mortality more effectively than other available means.2,3 The recent decline in CRC mortality has been attributed to the wide-scale implementation of CRC screening and, because all screening strategies involve colonoscopy as either a primary or evaluative instrument, this seems to further support colonoscopy as the best intervention.
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