Introduction Adynamic or paralytic ileus is a common condition in the experience of most physicians. Surgeons are especially familiar with ileus of this type subsequent to abdominal trauma or laparotomy or associated with generalized peritonitis. Characteristically the small and large bowel are involved simultaneously to a greater or lesser degree. The possibility of ileus limited sharply to one section of the bowel is less well recognized. Occasionally in patients with acute pancreatitis one or two loops of dilated proximal jejunum will be visualized on a plain x-ray film of the abdomen. However, the discovery of a greatly distended large bowel in the absence of significant small bowel involvement is almost pathognomonic of obstruction or mesenteric vascular injury. In recent years we have seen eight adults presenting with abdominal enlargement of major proportions. All of them had marked distention confined largely to the colon without evidence of mechanical obstruction of the