Might be histamine intolerance. Try eating fresher food for a few weeks to check

Time to get a coloscopy.

This is anecdotal of course and TMI but honestly same with my IBS-D. I tried keeping a food journal for a couple months - didn't matter what I did or didn't eat no through line stuck out.

Seems my main trigger is anxiety and stress which sucks because there isn't too much to be done about that at times.

Cutting down on coffee helped me some but still enjoy a cup a day or maybe a couple cups - same with caffeine in general - slamming a couple energy drinks paired with a coffee or two - recipe for poop city (probably goes for most folks though).

Anyways you're not alone in your whole, "I have some weird stuff going on with my GI tract and it doesn't seem to line up with any dietary restrictions". As always, a chat with a doc is not a bad idea, you might be able to find some relief.

Best of luck on your journey.