@ilean I did think of a few things that may (or may not) be helpful...

I was diagnosed several years ago with collagenous colitis. (Yes, it is as lovely as it sounds.) Two different dr's told me the "cure" is to take 8 pepto bismol chewable tablets a day every day for 8 weeks. (like 3 in the morning, 2 at noon and 3 at night) I thought it was crazy....but I was desperate, so I tried it. The first few weeks, nothing changed, but slowly over time, it actually really helped. I have started the regimen again, and now 2 weeks in, I am seeing improvement.

I also take powdered psyllium husk which works well (sometimes too well). And recently I was told to try millet -- which is surprisingly yummy -- and that seems to really be helping as well. I've actually had a few near normal days lately and I feel hopeful.

Of course, I am not a dr. I only wanted to share what seems to helping me stave off weight loss and function to some extent, while I continue to work to get answers from the medical community.