I had a colonic interposition in 2001 for reasons somewhat similar to yours, with similar discomfort and misery, but after a few more surgeries and a little time, most of my symptoms went away. I have to eat all the time and diarrhea is continuous. Pain is an inevitable problem for me after meals, but my pain is more generalized, occupying the whole abdomen. It’s effectively eliminated by taking a tablet of Percocet (Oxycodone/acetomenophen), a potent restricted narcotic, 3-4 times a day on average. The pain relief appears not to come from its analgesic effect, but from its ability to slow and narcotise the intestine. Perhaps you can contact a pain doctor for advice on that. Colonic interposition is a rare procedure, so we are in a select crowd where most doctors haven’t a clue about what to do about pain. Copy my email and ask him/her to phone, if narcotics are hard to get where you are. Ask him to give it a try. Good luck and best wishes...and send me a private message if you think I can help.