Colonoscopy is the visual examination of the lining of the colon (large intestine) and the rectum.  This is done by inserting a flexible colonoscope through the anal opening, and then carefully maneuvered through the entire colon.  Depending on the findings on the exam, certain therapeutic techniques may be needed including removal of precancerous polyps, biopsies of abnormal appearing colonic lining, or stoppage of bleeding sites using electrical cautery and other techniques.  The procedure is done while the patient is under sedation and monitored by an anesthesiologist.  Prior to the procedure, the patient is given a medication to completely cleanse the colon.

A colonoscopy is often done to evaluate for a variety of colonic diseases and symptoms.  These include: