Have you read about the "eat right 4 your blood type" ?
- a lot of it fit for me & my blood type.
Certain foods would make me feel bloated or just not comfortable and after I read the book I could see why.
Most of the foods that kind of bothered me were the ones I shouldn't have been eating.

The guy has a website and his books are in the libraries if you are interested in looking into it more. http://www.dadamo.com/knowbase/newbie/1.htm