Well maybe you could include that part then.
This may sound random, and I never had IBS so can’t promise it would help, but I found aloe juice to be really amazing for digestion. It’s not super cheap, but nor is it very expensive, and you can have a small glass (like 2 oz) a few times a day. You’ll know within drinking the first bottle if it works for you or not.
(My one recommendation here is get the stuff with zero additives – I like the lily of the desert in the glass bottle. When I tried the same brand in a plastic bottle, I found it disgusting, and I think it’s because it has an added preservative.)