I found this article about a study of Rectal bismuth subsalicylate ( bismuth subsalicylate is essentially pepto bismal) as therapy for ulcerative colitis. It seemed very promising and that is worked for people so I wonder why this was never developed as a treatment?? Could it be because they make more money off of us being sick and miserable?
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2036.1990.tb00480.x