Ileo-sigmoid knotting is an uncommon lesion that has a high mortality (27.3% in this study). This is due to the rapidly deteriorating systemic disturbances that can follow gangrene involving both the ileal and sigmoid loops (63.6% of cases had gangrene of both loops in this series). Isolated gangrene of the sigmoid colon is uncommon. The recommended treatment consists of resection and anastomosis of the small bowel, and a Mikulicz type exteriorlsation of the gangrenous sigmoid. However, Hartmann's procedure is recommended when gangrene has extended down to the upper rectum.