I've had colitis for 15 yrs now and in the early years I was given a lot of conflicting advice on what to eat and what not to eat. That conflicting advice still seems to be around. Different food upsets different people. I found the best thing to do was to keep a food diary, also writing down the reaction my guts had, pain bleeding etc. In that way I was able to work out what suited me. I avoid onions, beans, coleslaw - all these dificult to digest foods. Fried things can upset me too.