Cystectomy is a medical term for surgical removal of all or part of the urinary bladder. It may also be rarely used to refer to the removal of a cyst, or the gallbladder. The most common condition warranting removal of the urinary bladder is bladder cancer. After the bladder has been removed, an Ileal conduit urinary diversion is necessary. An alternative to this method is to construct a pouch from a section of ileum or colon, which can act as a form of replacement bladder, storing urine until the patient desires to release it, which can be achieved by either abdominal straining or self catherisation. Future treatment for this condition may involve a full replacement with an artificial bladder.

One of the follow-up solutions to a cystectomy is the creation of a neobladder (one form of which is named Studer's Ileal Neobladder or the Studer Pouch). A neobladder is a loop of intestine that is surgically fashioned into a pouch and placed in the location of the original bladder. It is then attached to the ureters and the urethra, thus simulating the function of the original organ. The kidneys filter the urine into the neobladder which can often be emptied by muscle control. There are side effects of this complex surgery, including partial shut down of the digestive system (in response to removal of the piece of intestine), incontinence, and the loss of the nerves that signal a full bladder.

From http://en.wikipedia.org/wiki/Cystectomy