I don't know the answer to that question but I have wondered myself if taking Immodium can cause long term problems like that. I have been taking it for two years now and think about all kinds of things like that that could happen from sloweing things down with Immodium. Although I hve never heard fo Ishemic colitus until this business about Lotrenex came about. I worry about toxins staying in and causing problems...but then again nothing seems to stay in me very long even with the Immodium..so maybe it's no more than if you're constipated naturally...those people dont' seem to get colitus!