If your bladder or urinary system is damaged or diseased and you are unable to pass urine normally, you will need a urinary diversion. This is called a urostomy or an ileal conduit.
During a urostomy operation, an isolated part of the small intestine is brought onto the surface of the right-hand side of your abdomen and the other end is sewn up. The ureters are detached from the bladder and reattached to the isolated section of the intestine. Because this section of the intestine is too small to function as a reservoir, and there is no muscle or valve to control urination, you will need a urostomy pouch to collect the urine.
(Source: Coloplast)