In 1904 Sir William Macewen,1Regius Professor of Surgery at the University of Glasgow, in his lecture on the cecum aptly stated that just as the informed citizen learns world geography by perusing the news of foreign wars so the clinician becomes involved in anatomic studies by skirmishes with clinical problems. Thus, anatomical consideration is given the so-called ileocecal valve because of interest in problems of acute large bowel obstruction. This structure supposedly prevents regurgitation of colonic material and gas into the ileum and so accounts for the status of "closed loop" in obstructive lesions of the colon.2Allegedly, 10% of these valves are incompetent, because the inferior leaflet is absent. In such cases, the obstructed colon supposedly decompresses itself into the small intestine. In our experience a much larger percentage of acute colon obstructions exhibit signs of associated small bowel obstruction, and scout films of the abdomen