• A form of intestinal obstruction caused by the prolapse of a part of the intestine into the adjoining intestinal lumen. There are four types: colic, involving segments of the large intestine; enteric, involving only the small intestine; ileocecal, in which the ileocecal valve prolapses into the cecum, drawing the ileum along with it; and ileocolic, in which the ileum prolapses through the ileocecal valve into the colon.