What causes food allergies? i keep developing food allergies, and my doctors have no explanations. i also have ibs-c. is leaky gut a real disease? could it be causing my problems? (all i eat is fiber)

First, you need to: make sure what you are experiencing are true allergies. Many people have food intolerances--nausea, pain, diarrhea--but often food allergy also involves hives, itchy skin, shortness of breath indicating an activation of your immunologic system. Having IBS leads me to favor the food intolerance diagnosis. Leaky gut, as you suggest, isn't a recognized diagnosis.Fiber is good, but more balance needed