Mac,
My theory:
They remove the cystoscope (after taking the biopsies)
Urine starts to fill up the bladder
Urine hits the sensitive areas that the biopsies left
Bladder goes into spasm
At least that's what happened to me after deep TURB
Catheter stopped spasms immediately, in my case, since the urine drained out before it hit the TURB spot giving it a chance to heal.
I don't know why they made you wait so long before giving the morphine; probably had to find a Dr. to sign off on the meds.
I apologize if this seems elementary but I'm still learning myself about all this stuff.
Bob P