To be honest, since I started the anti-depressents I can eat pretty much anything within reason as long as I rotate it. Too much dairy is very bad (it makes my ears and sinuses go funny), as is too much potato. I don't eat much red meat but a little bit of ham is OK. Marmite is strictly rationed because of the yeast.
Monster munch are good for me because they are corn rather than straight potato.
Sugar always makes me sick, as does fruit and veg on an empty tum. So do sugary drinks, or drinks and sweets with sweetners in them.
It's another matter if I get tired, nervous or ill- then its straight back to the IBS diet for me!!
Oh and exercise really helps, so if I don't do that I have to be careful.