I think i'm allergic to something. i get very bad bowel pain. and i have glactosemia?

Food Diary: You can see an allergist and have food allergy testing, You may also want to consider keeping a food diary of the foods you eat and see which ones are associated with your symptoms. If you review the diary and see an association, try avoiding that food for a period of at least two weeks and see if symptoms improve. You can always have a food intolerance or sensitivity without having an allergy.