The results of diagnostic colonoscopy in the management of unexplained bleeding from the rectum.

A consecutive series of 71 colonoscopies performed for unexplained bleeding per rectum is reported. All patients had had previous barium enema examinations reported as normal. In 26 colonoscopies lesions were detected; there were 12 cancers and 11 polyps. Twenty-five of these lesions were in the left colon. These findings illustrate the value of colonoscopy in supplementing the available radiological findings. The sighting of blood at sigmoidoscopy was associated with a lesion found on colonoscopy in most instances, whereas the presence of occult blood was associated with a lesion in very few. Colonoscopy should be considered prior to laparotomy in every case of unexplained blood in the stools.