Work in progress. The anal canal: distinction of internal hemorrhoids from small cancers by double-contrast barium enema examination.

Sixty-six patients with normal anal canals, 66 patients with internal hemorrhoids, and 6 patients with small cancers in the anal canal were examined by double-contrast barium enema examination. Internal hemorrhoids appeared as single nodules in 3 patients, multiple nodules in 59 patients, a polypoid mass in 3 patients, and a varicoid mass in 1 patient. Small cancers appeared as slightly irregular polypoid masses in 5 patients and as a plaque-like lesion in 1 patient. The sensitivity for detecting internal hemorrhoids was 83%, the specificity was 88%, and the overall accuracy was 86%. The sensitivity for detecting small cancers in the anal canal was 83% and the specificity was 98%. Internal hemorrhoids and small cancers in the anal canal can be easily detected and distinguished from one another by double-contrast barium enema examination.