DIVERTICULOSIS of the colon is a relatively common entity. The frequency as found on barium enema examination varies from 5.2%, according to Rankin and Brown,1 to 8.2%, according to Willard and Brochus.6 While diverticula occur throughout the large bowel, by far the most frequent site of involvement is the sigmoid. Of all patients with sigmoidal diverticula, 47% present only sigmoidal diverticula, but the sigmoid is involved in combination with other sites in 95% of cases.2 While the x-ray diagnosis of colonie diverticula is usually established by use of contrast material which may be administered orally or per rectum, the diagnosis may be made from a plain film of the abdomen. The air-filled diverticula appear in an area of slightly increased soft tissue density within which are multiple, small, rounded lucencies that give a bubbly configuration. This is most commonly seen in the lower midabdomen or in