Is biopsy necessary if colonoscopy is normal?

Multiple endoscopic biopsies were taken from 100 consecutive patients who had a macroscopically normal colon at colonoscopy. Of these, 78 were regarded as histologically normal; 13 cases of melanosis coli, 7 cases of intestinal spirochetosis, and 2 cases of collagenous colitis were identified. In no cases was there histologic evidence of inflammatory bowel disease. Histologic abnormality could not be predicted by retrospective analysis of various clinical, hematologic and biochemical data. In individual subjects the microscopic abnormality was present to a varying degree in all biopsies, except in intestinal spirochetosis where patchy distribution occurred in some subjects. It is therefore concluded that significant pathology may be missed without biopsy of the apparently normal colon, but in order to reduce the workload of pathology departments and shorten the duration of the examination two biopsies from the hepatic flexure and sigmoid colon may be adequate.