(I had proton radiation at UC 5 years ago.)

There’s no way to know why your 3+4 became a 3+5.
> it may have been due to better sampling of the MRI guided biopsy.
> the “5” may have been there initially, just too microscopic to see.
> they may have simply missed it (given that Gleason scores are educated opinions).

As for pre-existing bowel issues, Dr. Rossi has information about this (& proton) in his portion of this 2023 Mid-Year PCRI presentation: https://www.youtube.com/live/WTqPnSRYtW4
—> Starting at about 4:48:15:

As for the “downside of radiation seems to be in 2 to 3 years some of the same side effects start to appear as surgery” depends on how much radiation overshoot there is that hits otherwise healthy nearby tissues and organs. Taking precautions in advance and during treatments is absolutely necessary.

(Diagnosed with prostate cancer in April 2012, I was on active surveillance for 9 years, I had proton radiation at UC five years ago (April-May 2021): 28 sessions (@ 2.5 grays per session) + 6 months (two 3-month injections) of Eligard. I also used SpaceOAR Vue. I also was not a candidate for focal therapy, having lesions on both sides of my prostate.)

For me - after years of research - proton beam was the right choice.

Best wishes on your decision.