deedee74,
I didn't send you this information because I hadn't time to recover the link. There is another treatment https://link.springer.com/article/10.1007/s12029-026-01458-2 Reading the article is more important than reading what happened to me. But before I go on, I'd suggest that you start with HBO.

I had primary rectal cancer, which being rare complicated my treatment. I didn't want chemotherapy which delayed treatment. I had 28 session of proton radiation which is less harmful to surrounding tissue but was a direct hit to the rectal epithelium ruining the capillaries there.
During my first rectoscopies the doctor kept telling me how beautiful my rectum was. I thought it was GI humor which can feel strange, but the screen exhibited the smooth white surface of avascular skin that would slough off soon enough, yielding to the second stage irregular, damaged vessels that can't support the epithelium and just bleed. The pathology of radiation damage is cyclic.
All of the oncologists I consulted told me I'd just have to get used to the bleeding. Until searching led me to this article. https://pmc.ncbi.nlm.nih.gov/articles/PMC3539292/ So I called Rodney Edii. He was wonderful, warning me about pinpoint RFA and the importance of having this done with a Halo wand. This wand which looks like a tiny, tiny flyswatter is attached to equipment that controls the time and depth of the radiofrequency. He speculated what has since been proven -- not only does the regrowing epithelium normalize, but the space between treatment spots recovers from the radiation damage. Pinpoint RFA is too deep can be too strong and only stops the bleeding temporarily unless if forms scar tissue--which you don't want.
Eddi couldn't perform the treatment because he was at Sutter where they don't have the equipment.
It took some time to find a practitioner with access to the Halo, partly because the first doctor I called didn't respond. I scheduled at Scripps, but a data breach made them cancel all unnecessary procedures. I scheduled at Stanford even though the doctor hadn't ever performed the procedure. Cheers to him for being willing to try. But truly out of the blue-- I was floating on a pool of water staring at the sky-- when my cell phone rang. It was Dr Buxbaum at USC, who does the procedure all the time, finally returning my call. I could make this even longer by talking about Buxbaum and the amazing staff. I should tell the story of nurse Lulu sometime.
I returned four or five times until now. I am completely over radiation proctitis.
HBO is slow, but it's good for your entire body, even your bones. I had ten sessions before I noticed that the PM95 filtration they'd bragged about was a filter in front of the air vent that never stayed in front of the vent. I might have risked Covid for myself to get rid of the anemia from proctitis, but couldn't risk it for others close to me.
Hyperbaric oxygen didn't resolve the bleeding, but I'm convinced it would have with additional treatments.
I think you'll have good luck.