Double-contrast radiography: colonic inflammatory disease.

Double-contrast examination and proctosigmoidoscopy were performed in 240 patients with ulcerative colitis and 60 patients with granulomatous colitis. Both examinations were evaluated for accuracy of detection of disease, accuracy of classification of disease, and the ability of one examination to add information not gained by the other. Endoscopy was more sensitive than double-contrast examination in detection of disease of the distal colon and rectum in 18% of cases of ulcerative colitis and 17% of cases of granulomatous colitis. Double-contrast examination was more specific than proctosigmoidoscopy in differentiation of disease in cases of ulcerative colitis; endoscopy incorrectly classified 11% of cases as granulomatous colitis, and double-contrast examination misclassified only one case (less than 1%). Neither examination misclassified a case of granulomatous colitis as ulcerative colitis. Finally, double-contrast examination demonstrated disease proximal to the range of the proctosigmoidoscope of a greater severity than that seen endoscopically in 24% of patients with ulcerative colitis and 70% of patients with granulomatous colitis. Radiographic variations in disease presentation occasionally caused difficulty in classification. Double-contrast examination and proctosigmoidoscopy are complementary, and both should be used in evaluating patients with inflammatory disease of the colon.