Dear Brownley - I have had at least 4 bouts ( lasting over 5 weeks or so each ) of significant pain up my backside and around my testicles at times . Last year I had a colonoscopy to investigate and the consultant said the pain was from radiation proctitis from my course of radiotherapy in 2008.
A few years ago I also noticed blood in my ejaculate which was a real worry as it went on for a number of months - my urologist arranged a cystoscopy which showed enlarged and damaged blood vessels again resulting from previous radiotherapy . He said it was therefore a " cosmetic problem" and best left alone. Things resolved themselves and I no longer have this leakage of blood.
I hope this offers some comfort and support - always needed when you are worried.
I have searched this forum often in the past for advice and support and have come across some of the most wonderful, kind and thoughtful people.