Hi, Thanks for writing in. The nerve supply to urinary bladder, rectum and testis are closely related. These nerves originate in the lumbar segments of spinal cord which is in the lower back. There must be a nerve getting stimulated or irritated due to the bladder cancer which is also supplying the anus and testis. This might be causing pain to be felt. Surgery for urinary bladder removal is a major surgery and recovery might take some time. However, the severe pain will improve but mild pain might persist for a few weeks till the surgical wound heals completely. In 3 months time after surgery the wounds should be healing well and his pain will likely improve. The testis pain should disappear by then. Please do not worry.