I’ve recently moved to a meat heavy diet, and that pretty much fixed my ibs completely. I still get flare ups if I eat too many oranges or bananas, but eating meat on every meal is absolutely essential.
This is the thing that's tripping up health professionals about gut health, people's guts are really different and there's no official accepted way of testing what kind of diet works for who.
Except for long-term experimentation and elimination and that's not "scientific", so we don't do that. Doctors just want to prescribe a pill that' fits everyone[0] and call it a day.
[0] everyone they bothered to test it on, so mostly white western males