I second the Dr. Threkle at Restorative Health in F Heights, DC, she was such a help to me before I even knew I had any of these intolerances, I wasn't feeling well, and she worked with my insurance to do some VERY expensive
testing for a good price. If for any reason you cannot afford the testing, I would agree with the p. poster and go with a do it yourself kind of elimination. The only problem with that, is you may also be sensitive to certain veggies or fruits.