I just thought id put my two cents in..its not worth much mind u but here it is...

Have you ever been evaluated for celiacs disease? My godmother was randomly fainting all the time. She had been looked at by so many doctors and no one could understand why she kept fainting. Here it was celiacs disease. Its a disease that you cant handle gluton foods and if you do intake gluton (which i know you do because almost everything has gluton) one of the symptoms is fainting. I would try and bring it up and ask for a gastro doctor. Good luck!