Ileal J-pouch-anal anastomosis is a commonly accepted surgical treatment for patients with ulcerative colitis. However, making a J-pouch anal anastomosis can be difficult due to anatomical variations of patients. We experienced an informative case of ulcerative colitis in which the ileal pouch was damaged when it was pulled down into the anal canal because of a fatty short mesentery. To preserve intestinal consistency and functioning fecal continence, a modified H-pouch was converted from a damaged J-pouch and anastomosed to the dentate line. This operation achieved a satisfactory functional result and, we believe, presents an option for reconstructing ileal J-pouch-anal anastomosis.