The role of sigmoidoscopy and colonoscopy in the diagnosis and management of lower gastrointestinal disorders: technique, indications, and contraindications.

Flexible sigmoidoscopy and colonoscopy have revolutionized the clinical management of colonic diseases. Colonoscopy has a broad range of indications, including evaluating lower GI symptoms such as lower GI bleeding, evaluating abnormal radiographic findings, and screening and surveillance for colon cancer. Colonoscopy is increasingly being used therapeutically. Patient evaluation, patient instructions, and colonic preparation before colonoscopy are essential for safe and efficient colonoscopy. Intravenous sedation reduces patient pain and anxiety during colonoscopy, but requires monitoring by pulse oximetry and automated measurements of vital signs. An experienced colonoscopist can complete colonoscopy in 90% or more of cases, using maneuvers to maintain the colonic lumen in view, straighten the colonoscope, and avoid looping during colonic intubation.