Value of colonoscopy in patients with rectal blood loss unexplained by rigid proctosigmoidoscopy and barium contrast enema examinations.

Total colonoscopy is the procedure of choice for patients with any amount of rectal blood loss unexplained by proctosigmoidoscopy and barium contrast enema examinations. In 168 endoscopic examinations, 46 unsuspected lesions in 39 patients (23 percent) were detected, 50 percent of which were 1 cm or greater in diameter. Considering that 30 percent of all unsuspected lesions, 100 percent of angiodysplastic abnormalities and 40 percent of unsuspected carcinomas were located proximal to the splenic flexure, emphasis is placed on the importance of examining the entire colon to the cecum.