i have a hard time w/ making healthy choices and avoiding the foods that trigger me too, loth. What i have found is making sure you eat enough soluable fiber...it sort of "gels" in your intestines, and i have found that since i have been eating asparagus daily (:P), that my stomach is soooo much better, at least on a good run of time. I know it can be super frustrating, but i think finding a routine, when your belly is relatively settled, is the best.
Have you tried meds? i dont normally advocate this, but i have been prescribed liquid opiate...which slows everything down.... being on it daily for a really short 2months or so, *really* helped settle my belly. WHen you are having constant diah., you are causing inflammation in your intestines, which in turn, makes you more sensitive to EVERY food! being able to allow your body to regenerate its intestinal cells will help w/ digestion. NOw, you may not have to go as far as the opiate med...kaopectate or other OTC meds may work fine for you, depending on your severity.
BUt i tell you, its nice to not have to worry so much, carrying around a medicine cabinet full of meds all the time!
plus, as you may know, if you have chronic diah., you wont be absorbing nutrients properly.
also, i know you avoid fruits, i myself have to be picky about them too, but have you tried bananas? they seem to do me good.