I have been underweight all my life and recently I was explicitly told by a vascular surgeon that it's making my IBS symptoms a lot worse. Without enough fat to keep things nice and separate and padded, things are becoming much too tightened inside. However, I can't tolerate most meats (pretty much just lean fish and poultry) and obviously a big fat load is a big symptom trigger too. I want to put on weight, always have, but now that it's pretty much life or death at this point, does anyone have some advice on how to do that? I already have 5 small meals a day with a protein source in each, and cassein+whey have been dangerous in the past, so any further suggestions would be welcomed and do me a lot of good.