Thanks for your query.You have not mentioned age of your father in your statement.He has undergone endoscopic surgery
of TURBT for resection of a Bladder tumor
.What was the status of Prostate Gland on Ultrasound
Scanning which might have been done before surgery. Was it Enlarged or Normal.? If he had a enlarged prostate
this could be the reason for difficulty in passing urine.As such any instrumentation in urethral passage precipitates the spasm of Sphincter of Urethra resulting in difficulty in passing urine.If he is to much in agony Catheterize him again and keep it for 10 to 15 days Normally it settles in 2 weeks.You can give him antibiotics and Bethanacol after consulting your Urologist
who has performed the surgery.