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Food Protein Induced Enterocolitis Syndrome (FPIES)

What Is Food Protein Induced Enterocolitis Syndrome (FPIES)?

Food protein induced enterocolitis (en-ter-oh-coh-LIE-tis) syndrome, also called FPIES, is a type of delayed food allergy. Hours after eating certain foods, a child might vomit several times, have diarrhea, and be very sleepy. Having repeated episodes of vomiting and diarrhea can cause a child to lose lots of fluids and get dehydrated.

FPIES is different from traditional food allergies that cause reactions (like hives, trouble breathing, or vomiting) soon after eating a food. Because the symptoms are delayed, it can be hard to diagnose FPIES until a pattern is noticed.

What Is Chronic FPIES?

Some babies have chronic (long-lasting) FPIES when something they are fed often (such as cow’s milk formula) causes problems. Besides vomiting, a baby may have trouble gaining weight and growing.

What Foods Are Linked to FPIES?

The most common foods that trigger reactions with FPIES are milk, soy, rice, and oats. But any food can lead to FPIES reactions. Often, children react to only one food, but some have reactions to multiple foods. An allergist can help parents know what foods are safe for their child.

How Is FPIES Diagnosed?

No specific test can show if a person has FPIES. Sometimes, doctors order tests to see if something else could be causing the symptoms.

The allergist will ask about the reactions, what foods were eaten, and the timing of the symptoms after eating. They might do allergy tests to look for a traditional food allergy.

How Is FPIES Treated?

Someone with FPIES must avoid the foods that might trigger a reaction. If your child has FPIES, the allergist will give you an action plan to help avoid reactions, and to know how to treat reactions if they happen. Share this plan with all your child’s caregivers. 

During a reaction, kids often need to get fluids through an IV to prevent dehydration. Sometimes they also get steroids to help with reactions. 

Because FPIES isn’t common, ask the allergist for a letter you can give to emergency medical personnel explaining your child’s condition and how they should treat it.

What Else Should I Know?

Most children outgrow FPIES with time. To find out if a child has outgrown FPIES, the allergist might recommend doing an oral food challenge. The child will eat the potential food trigger, then be watched for several hours for symptoms.

You also can find more information about FPIES and support online at: