Concerned about my 4 1/2 yr old son who has been complaining of an upset belly , mostly in the am, but also throughout the day for about 6 months. At least 4-6x/ wk. He is very aggressive at times and when he ingests too much dairy his behaviors are uncontrollable. I have tried eliminating dairy from his diet but it has not helped his abdominal pain . He also has never really had a normal bowel movement . They are always soft, thin and often times contain mucous. I am throwing around all of the possibilities of food allergy/ intolerance, yeast syndrome , not really sure. Can any blood tests or skin tests be done to check allergy/ intolerance?