Thanks for choosing health care magic for posting your query.
I have gone through your question in detail and I can understand what you are going through.
The bladder surgery was done through urethra
and this can cause some local trauma. But then it is no need to worry. With time the pain will go off and until then you may just continue taking some mild painkillers.
Hope I am able to answer your concerns.
If you have any further query, I would be glad to help you. You just need to contact me on this below mentioned link:
Wish you good health,
Dr. Srikanth Reddy M.D.