Usually the transplant surgery takes two to three hours. Often the kidney begins making urine immediately. Sometimes, particularly if the kidney is from a cadaver, it may not make urine for several days to a few weeks after surgery. You would then need dialysis for that period of time. Even if the kidney is slow to start it usually returns to normal function.
Rejection is a term used when the body reacts against the transplanted kidney.
The transplant team will monitor you for any signs of rejection. Rejection is not unusual, and about a fourth of patients receiving a kidney transplant, experience a rejection episode in the first 12 months. A rejection episode does not mean that you have totally rejected your kidney and that it has failed. It means that your body has realized that the new kidney does not belong to you, and tries to fight the kidney off, just as your body tries to fight off an infection, cold, virus, etc. There are medications available to treat rejection.