I do believe in the problems of IBS. But some of what I'm reading here is common with allergic reactions (only) and not IBS.
My sister just realized (from my discussion with her) that she could get allergy testing and desensitization for the MSG that causes her terrible problems.
My allergist said all things in moderation.
Too much of anything is well, TOO much.
But that IBS... oh my ((((((hugs to all with it))))) Hope you find things that help you do and feel better.