A continent ileal bladder was constructed in six dogs. The most important requirements for a continent ileal bladder as a reliable mechanism of continency and for prevention of back flow in the ureters could be achieved by two intussusception valves (nipples) of small bowel in opposite directions. The dynamics of these "nipple valves" were studied electromanometrically and radiologically. These experiments showed that these intussusception valves did not binder a free flow in the isoperistaltic direction and did prevent reflux in the antiperistaltic direction.