Food protein-induced enterocolitis syndrome (FPIES) is an uncommon but severe non-immunoglobulin E (IgE)-mediated gastrointestinal food hypersensitivity reaction occurring mainly in infants. FPIES can be classified as acute or chronic.

FPIES most commonly occurs after consumption of cow's milk or soy products (usually in infant formula), but it may be triggered by solid foods as well. Eggs, fruits, grains, legumes, meat and poultry, seafood, vegetables, and the probiotic Saccharomyces boulardii have been implicated as triggers.

Typical presentation includes an infant with severe, repetitive vomiting, usually accompanied with diarrhea, developing within 1-4 weeks after introduction of cow's milk or soy protein. In the acute form of FPIES, patients experience sudden, repetitive episodes of emesis with resulting dehydration and lethargy. In the chronic form, patients experience intermittent episodes of emesis and watery diarrhea with weight loss and failure to thrive. Some patients may experience atopic diseases such as allergic rhinitis, asthma, or atopic dermatitis.

Treatment primarily consists of removing food trigger(s) from the diet and addressing severe, acute episodes in a clinical setting.