But it looks like your post mentioned rib. I get chest pain near my left breast that is pinpointed with one finger and confirmed not cardiac. Seems to happen after a gluten or soy reaction, but also for the same reasons above.
The slow motility can let food stay in the stomach too long and cause weird issues for some including pressure that can be felt under the rib area.
This is what I hate about GI issues. They mimic so much and the symptoms are very vague.