Sigmoidoscopy and Colonoscopy



Both rigid and flexible fiberoptic sigmoido­scopes are employed in clinical practice. Rigid sigmoidoscopy is a rapid, inexpensive procedure, but it is less well tolerated by the patient and per­mits less extensive examination of the rectosig­moid area. Sigmoidoscopy is commonly used to evaluate the cause of bloody diarrhea and to look for neoplastic disease of the rectosigmoid area. When the rectosigmoid area is involved, sigmoidoscopic biopsy will often suffice in making the diagnosis of inflammatory bowel disease with­out the need for colonoscopy. Colonoscopy en­ables visualization of the entire colon to the level of the cecum and is optimally employed in con­junction with barium contrast studies of the colon. Indications for colonoscopy include inves­tigation of suspected colonic neoplastic disease, surveillance for the development of malignancy in ulcerative colitis and polyposis syndromes, and diagnosis and evaluation of the extent of in­flammatory bowel disease.

Removal of colonic polyps for bleeding or to exclude malignancy is an important therapeutic application of colonoscopy. Colonoscopy has lit­tle use in patients with acute lower gastrointes­tinal bleeding, as considerable blood within the relatively narrow confines of the colon tends to completely obscure vision . An­giography is usually preferable in this situation.