I have learned the hard way not to eat raw oats, although well-cooked porridge seems to be ok.
It's funny you should say you have a problem too as generally people have been sceptical about oats being a cause and commenting that it is rare. I did the whole Fodmaps elimination diet and was told to try having foods with oats in it minus any dried fruit as they thought that might be the true culprit. Through that I did realise I feel better only having small amounts of dried fruit, but I felt terrible until I completely eliminated oats.
I eat lots of dried fruit :) It was the only treat we were allowed as kids!
But I pretty much ignore the existence of breakfast cereals because my tummy doesn't really appreciate even Weetbix or cornflakes.
I'm sure that I would die without morning cereals.