Ischemic colitis associated with sigmoid volvulus: new observations.

Ischemic colitis following conservative management of sigmoid volvulus is documented in four cases. Repeat barium enema studies in these patients showed characteristic "thumbprinting", transverse ridging, and mucosal ulcerations within a segment or the entire length of the sigmoid, lasting up to 7 days after nonoperative decompression. The development, extent, and severity of the ischemic changes seem to correlate with the degree of volvulus, blockage of venous and arterial circulation in the sigmoid mesocolon, and increased intraluminal pressure.