The impact of colonoscopy on the early detection of colonic neoplasms in patients with rectal bleeding.

A retrospective analysis was made of 372 consecutive patients who underwent colonoscopy because of rectal bleeding. The three distinct patterns of bleeding studied were chronic (224 cases), recent major (93 cases), and acute bleeders (55 cases). In 50% of the cases, colonoscopy detected a lesion other than diverticula. These lesions consisted of several forms of colitis, arteriovenous malformations (AVMs), ulcers, and most importantly, neoplasms in 34% of the cases. In 13% of the cases, an invasive neoplasm was detected and 76% of them were early stage (Dukes A or B). A third of the neoplasms were located proximal to the splenic flexure. Among patients with a negative barium enema, 35% had a neoplasm detected on colonoscopy. These findings were similar for the three distinct patterns of rectal bleeding studied. These data support the need for colonoscopy in all types of rectal bleeders, regardless of the results obtained by BE.