with kidney failure your first goal, a constant fight, is to lower your amount of fluid intake. In the two weeks before the call for transplant my daily fluid intake netted me zero urine production, down from a very modest urine output. In hospital a catheter was inserted for about five days. My new kidney began working immediately upon completion of surgery. The retraining of the bladder is simply teaching a dry stiff nonflexible bladder to recall the sensation of a fully urine loaded bla dder. In a short time bladder control should be reestablished. Not painful especially just odd sensation, back pressure esp. with the cathethter was peculiar. An essential urine check is creatinin level, on dialysis mine was up to 1200′ then more like 700-800, now down to about 170. Not every kidney works so well after transplant but mine has, I am fortunate. other transplants take a little more time to ramp up production, almost all do.