Is food allergy related to IBS?

Dr. Tobin: It can be. With a food allergy the abdominal pain or discomfort can be accompanied by itching of the lips, inside of the mouth, tongue or throat or can even cause swelling in these areas and make it hard to talk or swallow. Some people will report that they get an itchy nose, skin rash or hives with diarrhea. When a person has severe swelling, shortness of breath or dizziness, a person is said to have an “anaphylactic reaction” to that food and must completely avoid it and carry epinephrine for treatment. Allergic reactions to food usually occur within 2 hours of eating and will reoccur to some extent every time the food is eaten. In adults the most common foods to cause reactions are peanuts, tree nuts, fish and shellfish. People who have seasonal allergies or a history of allergic eczema (skin rash) may have food reactions that are worse in the spring or fall like their seasonal allergies. They may have reactions to fruits and vegetables that share proteins with the pollen. A reaction of itching or swelling that is limited to the mouth is known as oral allergy syndrome. Again, skin itching, diarrhea or even problems with shortness of breath can accompany oral symptoms with specific foods. These allergies may be harder to identify but a food diary with the time of onset after eating and symptoms, is an important first step to evaluating the role of food allergy with IBS. Some foods that commonly cause reactions in this way include apples, carrots, bananas, melons, cantaloupe, tree nuts and tomatoes.