THE PASSAGE of gross blood per rectum from a source above reach of a proctoscope is most commonly from a colonic neoplasm, either benign or malignant. Ninety-five per cent of benign lesions are precancerous adenomatous polyps,1 whose discovery and eradication may prevent the development of carcinoma. Diagnosis of such lesions is dependent upon the judicious use of competent roentgenologic technique of barium-air contrast enema examination. This report is based upon 100 patients in whom clinical investigation resulted in a roentgenologic diagnosis of one or more polyps of the colon. Patients with diffuse polyposis or with lesions suspected to be carcinoma are excluded. In all cases the diagnosis was verified by laparotomy and pathological examination. Diagnosis and definitive treatment will be discussed. DIAGNOSIS In each instance the principal presenting symptom was the passage of blood per rectum. In some patients there was a history of one or more acute gross