Weirdly, my body almost tells me what to eat. I can look at something and thing 'that won't sit well in my stomach'. Like if my parents are cooking a Sunday roast or something, I'll leave things out like cabbage and anything gassy. Sometimes my stomach will start to hurt more just contemplating eating a certain food, like it's thinking for me. Or like a voice telling me 'No, do not make me digest that!'
I tend to stick to the simplest of foods. Meat, eggs and certain vegetables. I too like potatoes or carrots, but I couldn't eat anything like broccoli, for some reason I just know what would make things worse. I agree soups are great too.
Always make sure to take sips of water during a meal too, I believe it helps with digestion and makes it easier for your gut, almost allowing it to pass through more smoothly.
Sorry if I haven't been a great help! Just keep it simple really.