There are basic rules, such as avoiding too much sugar, imbalancing the acid/alkaline nature
of your digestive system, too much
of the wrong kind
of fat but getting plenty of the right kind of fat. You want to be easy on your digestive system, and the stress angle is probably right. You might want to look into meditation or some other relaxation technique that relaxes your body. Personally, I'd go find a holistic nutritionist and experiment until you find a diet that heals you.