Offending foods do not have to be eliminated entirely from your diet if you have food intolerance. By keeping a food diary you can track what you eat or drink daily. Have it one day, but omit it the next day or so. Within a couple of weeks, you should be able to narrow down the main food offenders.
Food Allergies
Food allergies are an immune system response which occur when your body mistakes an ingredient in food, usually protein, as a harmful invader. Many people are surprised they have a sudden food allergy.
Simply put, by eating something once your body decides not to accept it so it begins building a defense system by making antibodies. Eat it again; food allergy symptoms develop when the antibodies and the food begin to battle one another. The first attacker is most likely histamine.
Well-known food allergies are peanuts, walnuts, pecans, almonds, milk, wheat, fish (mostly shellfish), eggs, and soy products. Other food allergies which might be surprising to you are fruits, especially melon, watermelon and even oranges.