Well, I have a lot of bowel issues and was curious about your situation. I read a piece from the UK's National Health Service and learned that sections of the gut can become inflamed from prostate radiation treatment. Getting shingles perhaps didn't help.

For me, gut inflammation can be healed via protein in the diet that is easy to digest. For me that would be egg whites, milk, protein powder, tofu, mild fin fish) I eat no more than a tablespoon of meat as it is harder to digest. I skip high-fat foods. To heal, I also need to eat other gentle foods that are easy to digest. Pureed veggie soups and hot cereal would be something like that.

If your gut can handle it, kiwi (1-2 a day, try 2 to start) acts as a natural stimulant for elimination. Slippery elm inner bark powder (add boiling water to make a "tea") supports the gut's mucosa, and that will help your gut heal. Magnesium supps can be a gentle aid to elimination (look at the Hilma brand). These three things keep me regular; without them, it would be another story.

Some laxatives can be harsh. Using them could prevent your gut from healing. I find that Colace Plus (stimulant and softener in one) to be the gentlest OTC if I have to use one.

The NHS article:
https://prostatecanceruk.org/prostate-information-and-support/living-with-prostate-cancer/bowel-problems#:~:text=Radiotherapy%20for%20prostate%20cancer%20(external,passing%20more%20wind%20than%20usual