Comparison of colonoscopy and the contrast enema in five hundred patients with colorectal disease.

Endoscopic examination of the entire colon (colonoscopy) is an important new method of diagnosis and treatment of diseases of the colon and rectum, particularly cancer. The records of 500 patients who had one or more contrast enemas and subsequent colonoscopy were analyzed in an attempt to evaluate the competitive and complementary features of the two methods. The endoscopists had the advantage of having a radiologic report or radiographs available to them. In general, when the level of abnormality could be reached, colonoscopy had a higher degree of accuracy, particularly since observation could be combined with biopsy. This was particularly true in the case of polyps in which colonoscopy confirmed 166 radiologically described growths plus an additional 118 lesion, twenty-one of which were over 1 cm in diameter. By endoscopic excision of these polyps via the colonoscope, malignant changes can be identified, a conclusion rarely reached by radiographic means alone. With respect to cancer, exclusive of polyps, only twenty-four of thirty-two cases were diagnosed by x-ray study alone. Another nine, interpreted aa demonstrating malignancy from the radiographs, had cancer excluded when subjected to endoscopic confirmation. Colonoscopy has also proved valuable in identifying lesions of the cecum, notoriously a problem for the radiologist, and in identifying milder degrees of inflammatory change which are undetectable by radiographic means. Colonoscopy and the contrast enema are best reported as completmentary rather than competitive approaches, and by their combined use, diagnostic accuracy is greatly enhanced.