I had it done a while ago. They catheterized me, which was not that bad. I was anesthetized. It was all done, because I had a gray area on a CAT scan, between my kidney and ureter, not urethra, so they were going through the bladder and up towards the kidney with the scope.
Apparently I went south on them, the 4th or 5th time the doctor tried to put the scope in the ureter. They gave me succhanocoline, which they would not ordinarily do.
When I woke, I had to piss so bad, it was unbelievable. By the time someone could get there, I had pissed myself involuntarily. Bladder agony was mild compared to the razor blade feeling of pissing.
I had not been aware of the many attempts, nor of the anesthesia. The next day, I was in so much pain, I could not chew a bean, nor push a shopping cart. I felt like 20 guys had beat the shit out of me, while I was under. I got painkillers from my regular doctor (a saint). Every single muscle from my waist up ached. My wife did some research, and found that this is a reaction to succhanocoline.
I had prostate surgery not long afterward. I requested that they not use succhanocoline. The anesthesiologist said, "They would never have used it on you, for a cystoscopy." When he looked up the records, it had been used.