Thirty patients underwent Mainz pouch construction between December 1992 and January 1998. The post-operative observation period varied from 6 to 57 months (average, 38.5 months). A mechanism to ensure urinary continence was provided in 24 cases, while formation of a nipple valve by intussusception of the ileum with seromuscular stripping and submucosally embedded in situ appendix was performed in 6 cases. An umbilical stoma was adopted in all cases. Late-phase complications included 3 cases of hydronephrosis requiring treatment. Efferent limb of the stoma was observed in 8 cases, 6 of which were attributable to mild constriction of the stoma at the site of anastomosis of the navel cavity. In those cases in which stomal stricture occurred, difficulty in withdrawing urine was eliminated by providing a fistula stopper. Although few clinical methods to deal with stomal stricture have been reported, we found the fistula stopper to be useful providing good external appearance and patients' quality of life.