Does anyone regret having radiotherapy ?

Of course, the other side of the coin is that you might have opted for surgery and suffered considerably worse side effects, ED and incontinence for example.  Clearly, those whose side effects are minimal and where the procedure was successful are going to be relatively happy regardless of which type of treatment they had.  Those who have not done well are more likely to wish they had had an alternative.  I don't think you can gather much from one or a few responses; you need the assessment of many men to ascertain whether in general significantly more men reget their choice.  Even then the result could be skewed because RT is given in cases where surgery might not do the job so patients hope RT will do it. 

Bit late but......I had ERT and hormone treatment in mid-2021, age 73. 4 years on and PSA has leapt to 2.9 on first of the planned annual checks. I do not however regret not having surgery,  although at my then age and with COPD Consultant didn't really give it as an option. The ERT process was easy and hormone side effects acceptable. 

Bought me 4 OK years at little inconvenience! 

Investigating, never mind treating (if possible), the obvious recurrence proving a long drawn out process but 4 years is 4 years.....

When I had a colonoscopy 2 years after the RT the signs of "over spray", pointed out to me by the radiographer,  were clear to see. Nothing else "remarkable".

I'm not sure how closely your diagnosis can be directly attributable to the RT. I have read of the possible link, but the odds are very small.

I think your regret is likely misplaced but in any case you are where you are, water, bridge, and all that.

I wish you the best of luck.

Dave.

The timeframe for increased risk of bowel cancer after pelvic radiotherapy is 10 or 20 years. That doesn't rule out unrelated bowel cancer now, but much more likely is radiation proctitis - basically an area of the rectum in contact with the prostate which has healed after the radiotherapy and has fine fragile surface blood vessels which easily break. This is a common side effect of healing after radiotherapy. This is harmless providing the blood loss isn't making you anemic or causing any other quality of life issue. It usually shows as bright red blood smeared on toilet paper when you wipe, and possibly a red line on the side of a stool (poo). It can happen in the bladder too.