The surgical removal of all or the greater part of the large intestine is done to relieve symptoms resulting from extensive disease of the colon. The ileum may be anastomosed with the sigmoid, the rectum, or the anus, or may be brought out through the skin to form a permanent ileostomy. A number of writers (1, 2, 3, 6, 7, 10, 12, 13) have observed that, as time passes, the intestinal contents discharged from the ileum under these conditions gradually become less fluid. This has been interpreted as evidence of increasing ability of the ileum to absorb water and thus make the stool of more normal consistency. In several cases, gross dilatation of the ileum was found at a subsequent operation (1, 2, 12). In a recent report Dennis and Karlson (5) state that enlargement of the ileum does not occur proximal to an ileostomy which is functioning properly. Mueller and Fischer (10) demonstrated increase in diameter and the development of large mucosal folds in the ileum of dogs following transplantation after excis...