Hi Siderman.  Welcome to the forum.

I had a TURBT in June, and a repeat cystoscopy just last week.

Did the hospital give you any painkillers before they let you go?  I had a box of 28 x 30mg codeine.  I know that it is safe to take paracetamol at the same time, as long as you scrupulously follow the dosing instructions for each drug.  Don't overdose on paracetamol. 

If you don't have any strong painkillers then your GP can prescribe some for you - if you phone now and say you're in pain you might get a prescription today.  

You can also buy from any pharmacy soluble paracetamol+codeine.  These contain less codeine than the tablets your GP can prescribe, but they should take the edge off the pain. 

FWIW, I had bad pain on urination for about 1 day after my TURBT, which I controlled using paracetamol and codiene tablets. It was surprising how rapidly the pain went from severe down to zero once it decided to go away.