Clinical and electro-manometric investigations were performed in six patients with ileoanal anastomoses. The results were compared with electromyographic and electrophysiological observations in the literature. It can be shown that decreasing motility, increasing compliance and a normalisation of the frequency of stools is possible after ileoanal as well as after ileo-pouch-anal anastomoses. Following both procedures high amplitude phase waves may persist in the distal and even in the proximal ileum. These waves can be stopped by voluntary contractions of the striated sphincter muscles if the patient becomes aware of them. During the night, however, uncontrolled defecations may occur. Un-isoperistaltic bowel segments will become isoperistaltic a few weeks or months after the operation. However, pouch-anal anastomoses show a better compliance and lower amplitude segmental or peristaltic waves than ileoanal anastomoses.