The Mainz pouch II procedure has proved to be a substantial modification of the classical technique of ureterosigmoidostomy at many institutions. To date we have used this procedure in 72 patients, including 15 children. Detubularization causes a low pressure and eliminates high-pressure contractions. Without the risk of compromising the blood supply the pouch is fixed at the promontory which reduces the risk of ureteral kinking and upper urinary tract dilatation as it is sometimes observed after ureterosigmoidostomy. The technique is not only indicated in cases of failed ureterosigmoidostomy but also for primary urinary diversion. Of the 72 patients operated, all are evaluable with a follow-up of 1-31 months. All patients are continent during the daytime with a mean emptying frequency of 5. All but one elderly woman are dry at night with a mean frequency of 1. The described urodynamic/rectodynamic evaluation enables a reliable prediction of postoperative continence. With the reservoir full the basal pressure was 24 cm H2O and the highest peak pressure recorded was 35 cm H2O.