The diagnosis of colonic obstruction.

The most common cause of colonic obstruction is adenocarcinoma, followed by diverticulitis, volvulus, and a variety of miscellaneous causes. Most signs and symptoms, from whatever cause, consist of abdominal pain with distention and the inability to pass flatus or stool. The clinical diagnosis is confirmed by x-ray studies. Plain films of the abdomen in various positions, chest films, and the addition of contrast studies verify the cause of the obstruction in most instances. The differentiation between neoplasm and diverticulitis causing the obstruction can be difficult or impossible at times, and may become apparent only after the obstruction begins to resolve with conservative management, or the cause is discovered at surgery. The history of previous abdominal or pelvic irradiation, surgery, and inflammatory bowel disease often causes difficulty in the differential diagnosis.