if you're really that worried about it, you could aways bring your own lunch. honestly though, my philosophy is to stay away from stuff with mayo, like egg salad, tuna salad, or potatoe salad. watch the buffet and go with what they just bring out, then you know it's fresh, note if the food worker is wearing gloves or something like that. with IBS stay away from stuff that's greasy or spicy. Usually I take some bread, meat, and veggies or fruit if it looks fresh. But really, there wouldn't be anything wrong with you bringing your own food.