Is colonoscopy necessary in diverticular disease?

Colonoscopy was carried out in 65 patients in whom double-contrast barium enemas for bowel symptoms had shown sigmoid diverticular disease. In 19 of these, barium enemas had shown neoplastic lesions--polyps in 17 and carcinoma in 2; but colonoscopy showed no polyps in 9 of the 17. In 1 a carcinoma not a polyp was found, and of the 2 carcinomas only 1 was confirmed. In 46 patients the barium enemas showed diverticular disease only, but colonoscopy revealed polyps in 8 and carcinoma in 3. Thus in 23 patients (35%) the barium enema was inaccurate. 13 of 20 patients with neoplasia but only 11 of 45 without had rectal bleeding, but the numbers in the two groups who had abdominal pain or change in bowel habit were similar in the two groups. Colonoscopy revealed neoplastic lesions in 20 of the 65 patients (31%), an incidence great enough to recommend routine colonoscopy in patients with symptomatic diverticular disease, especially those with rectal bleeding.