Hey, when I had the bad gall bladder, I could eat pizza and fried foods pretty well, which are the two biggest no-no's known to a bad gall bladder, but caffeine was a killer for me (much less of a known culprit). Even now I can't tolerate caffeine. After my surgery I went to where I could have some, then I couldn't tolerate it, then I could. I finally just gave up on the see-sawing back and forth and said, no, I will not have any caffeine at all anymore so I don't have to worry if this will be the time it bothers me.
I have definitely noticed that there are times my stomach is screwed up and it's not a matter of WHAT I eat but THAT I eat. I could eat crackers and rice and I would be sick. I could eat a big plate of greasy mexican nachos and be sick. That's hard for other people to understand sometimes, why you're eating a pizza when you're complaining about your stomach being off (if everything's going to bother you, might as well eat something you like--that's my motto), or why you're in the bathroom after eating two saltines, but that's just the way it is. When the stomach's off, it's off, and nothing short of fasting will keep you out of the bathroom (and even that won't keep you out of it completely).