Ileonal anastomosis through an extramucosal rectal muscular tube with construction of a proximal S-shaped ileal reservoir was performed on seven dogs in an attempt to reestablish fecal continence. Five of the dogs survived more than four weeks and experienced fecal continence, although they had frequent stools. The use of Lomotil and Metamucil has assisted in decreasing the frequency of defecation, and also in developing semisolid stools. None of the dogs developed perianal excoriation or ulceration. The ileal reservoir volume averaged 250 ml in the longterm surviving dogs. It is anticipated that this operative technic may have clinical application in selected patients with ulcerative colitis and other diseases primarily involving the rectal mucosa, since the neurogenic and muscular sphincteric mechanism necessary for continence can be preserved. Clinical experience with the ileal reservoir and endorectal pullthrough in one patient has been encouraging.