Sigmoidoscopy is an easy procedure and should be utilized more frequently. Barium enema examination is incomplete without sigmoidoscopy. Flexible fiberoptic sigmoidoscopy may have a role in the detection of disease of the descending, sigmoid, and rectosigmoid colon. The necessity for its routine usage remains to be determined. The control of colonic polyps by colonoscopy has been the greatest contribution to date by the fiberoptic instrument. Colonoscopy has improved the accuracy of diagnosis of colonic disease and, in certain instances, is helpful in the early detection of cancer of the colon. Colonoscopy complements the use of barium enema examination. Colonoscopy only for the purpose of confirmation of clinical or radiological diagnosis is often unnecessary. While the benefits of endoscopy are obvious, there are definite practical and technological limitations to its use. Complications, although infrequent, are major. Indications for colonoscopy must be clear and findings interpreted with knowledge of the limitations.