If he still has a catheter after prostatectomy surgery,the question will be how soon after surgery can he drive. Many of us on here advise talking to your insurance company following surgery.
Following many dilatations I was never told I couldn't drive , except for the first couple of days after general anesthetic. At one point I had both a urethral and suprapubic catheter at the same time without any issues. A kink or blockage in the catheter could cause a spasm and be a distraction, it has never happened to me when driving.
I have had a permanent suprapubic catheter for six years and have never been told I shouldn't drive and it doesn't cause me any issues.
Thanks Chris