Hello , welcome to HCM forum
will surely help you with your problem.
During the surgery for BPH
you would have been cathetrised so your symptoms of irritation may be due to the catheter or the surgery also. It will take 6 weeks for the inflammation to subside .so no need to worry symptoms will gradually disappear.
But i advice you to avoid constipation
,strenous activity or any sexual activity for 6 weeks.
Hope my advice's will help you.