This is a review of 181 consecutive colonoscopic procedures performed to resolve the etiology of colonic strictures when the barium enema was inconclusive. In 54 percent, it was possible to intubate the colon above the stricture and thus resolve the problem. In 46 percent, it was impossible to traverse the stricture. In this group, it was nevertheless possible to resolve the problem in another 13 percent using the combined technique of biopsy and cytology. Thus, colonoscopy was helpful and determinate in 67 percent.