I find this all very intereting. I have IBS (irrateable bowel syndrome) and they can't really tell you where it comes from as they diagnose you with it when all other possibilities have been excluded. I have found the medical profession quite useless and i really feel for your bubs when they have these attacks as such. I was told originally by a GP that you will just have to trial what you can and can't eat but without much help or guidence, the only person that has truely helped me is my wonderful Kinesiologist who has guided me every step of the way and is always just a phone call away. She sat me down and we went through everything from why i most probably ended up like this to an eating plan, supplements to help cope and to eleviate the toxins in my body.
I guess what i am trying to say is try a more natural approach as the natural therapists seem to be able to give you more answers and better outcomes than the conventional medical profession when it come to allergies and intolerances.

Best of luck