[Food intolerance--etiology of functional disorders and therapeutic possibilities].

Patients often complain about food intolerances and accuse them of causing diarrhea, constipation, meteorism, flatulence and abdominal pain. With alarm symptoms, patients usually suffer from structural diseases, which have to be clarified immediately by extensive diagnostic steps. With no alarm symptoms present, patients usually suffer from functional disorders. Their workup should be done stepwise. Therapy is dependent on the underlying disorder and often symptom-adapted. General measures of prevention for food-preparation and nutrition are important.