I find myself wondering why they do this as part of a cystectomy?
Taking some of the intestine away to form the conduit out, means interfering with that system, as well as the urinary parts. Surely with the advances in medical science, a purpose made piece of a suitable material could be introduced instead, allowing the bowel action to be left undisturbed, which should reduce the surgical trauma, and thus help recovery. Somebody before me must surely have thought about this, so must be a good reason why it's not possible I suppose?