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Overview of colonoscopy in adults

Linda Lee, MD
John R Saltzman, MD, FACP, FACG, FASGE, AGAF
Section Editor
Douglas A Howell, MD, FASGE, FACG
Deputy Editor
Shilpa Grover, MD, MPH, AGAF


Colonoscopy is used both diagnostically and therapeutically and permits examination and treatment of the rectum, colon, and a portion of the terminal ileum. Performance of a high-quality colonoscopy examination requires understanding and mastery of cognitive and technical skills. A joint American Society of Gastrointestinal Endoscopy/American College of Gastroenterology Taskforce on Quality in Endoscopy advocated the following quality indicators before, during, and after colonoscopy [1,2] (see 'Quality indicators' below):

Preprocedure – Attention must be paid to the general issues of timely scheduling, appropriate patient preparation, targeted history and physical examination, evaluation of bleeding risk, assessment for appropriate sedation, and team pause before commencing sedation. It is also important to understand appropriate indications and recommended surveillance intervals based upon the patient's risk factors (eg, family history of colorectal cancer, prior adenomatous polyps, hereditary colon cancer syndrome, or inflammatory bowel disease). Finally, obtaining informed consent with a detailed explanation of the risks associated with colonoscopy is essential.

Intraprocedure – Performing a high-quality examination requires careful visualization of the entire colonic mucosa. Metrics such as cecal intubation rates, withdrawal times, and adenoma detection rates serve as surrogate, though imperfect, markers of careful visualization. In addition, a high-quality examination requires appropriate tissue acquisition (eg, surveillance biopsies in inflammatory bowel disease) and endoscopic removal of all polyps less than 2 cm. Removal of polyps larger than 2 cm may require special endoscopic skills.

Postprocedure – There must be immediate, complete, and accurate documentation (both written and photographic) of preparation quality and findings, as well as explicit recommendations for follow-up. Tissue samples taken during colonoscopy must be documented. Pathology results should be reviewed with results and recommendations communicated to the patient and referring providers. Finally, there should be a system for tracking complications.

This topic will review factors associated with performing a colonoscopy including indications, patient preparation, technical aspects, and complications. Issues related to colon cancer screening recommendations, bowel preparations for colonoscopy, procedural sedation, and the management of antiplatelet or anticoagulant medications in patients undergoing endoscopy are discussed separately. (See "Screening for colorectal cancer: Strategies in patients at average risk" and "Screening for colorectal cancer in patients with a family history of colorectal cancer" and "Overview of colon polyps" and "Bowel preparation before colonoscopy in adults" and "Overview of procedural sedation for gastrointestinal endoscopy" and "Management of antiplatelet agents in patients undergoing endoscopic procedures" and "Management of anticoagulants in patients undergoing endoscopic procedures".)

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Literature review current through: Nov 2017. | This topic last updated: Dec 07, 2017.
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