A neobladder is a type of internal urinary diversion to replace a cancerous bladder.
A surgeon takes a segment of the intestine and uses it to form a new (neo) pouch for urine. This new bladder (neobladder) is attached to the ureters and the urethra, so urine passes through it like it would a normal bladder. By tensing the abdominal muscles and relaxing certain pelvic muscles, the patient is able to push the urine through the urethra normally.
This cancer eradication surgery, performed in Australia and many other countries, is closest to replicating a “normal” bladder due to loss of a bladder to cancer.
One of the downsides is that some patients experience leakage or incontinence. It takes time to train the new muscles in the neobladder and even with training the patient may not be completely continent. In some patients it may be hard to relax the urethra and urinate normally. Women, especially, may need to catheterize the urethra to drain the neobladder.