FPIES
Food Protein-Induced Enterocolitis Syndrome
Evaluation and management of severe non-IgE food reactions that cause acute vomiting, lethargy, and distress in infants and young children.
FPIES is a non-IgE mediated food allergy that causes dramatic, delayed reactions, typically two to four hours after eating a trigger food. In infants, this often presents as profuse vomiting, pallor, lethargy, and sometimes diarrhea, lasting for hours and leaving a child exhausted.
Unlike typical food allergies, FPIES does not show up on standard allergy testing. The diagnosis is clinical, based on careful history and, in some cases, an observed oral food challenge in a controlled setting. Dr. Mendez works with families to identify triggers, create safe feeding plans, and guide gradual reintroduction when the time is right.
Signs and symptoms
- Profuse, repetitive vomiting starting 1-4 hours after eating a trigger food
- Extreme lethargy, pallor, or limpness during episodes
- Diarrhea that may follow vomiting hours later
- Symptoms that resolve over several hours with supportive care
- Poor feeding or food refusal in older infants who associate eating with feeling ill
- Failure to gain weight if the trigger food is eaten repeatedly
How we treat it
- Detailed feeding and symptom diary review to identify patterns and likely triggers.
- Elimination diet planning with nutritional guidance to avoid the trigger while maintaining adequate intake.
- Supervised oral food challenges in a clinical setting to confirm diagnosis or assess tolerance over time.
- Coordinated care with allergists and dietitians for complex or multi-trigger FPIES.
- Family education on recognizing acute episodes and when to seek emergency care.
When to call a pediatric GI
- Your infant or toddler has delayed, repetitive vomiting after eating specific foods.
- You suspect FPIES but need a clear diagnosis and a structured feeding plan.
- Your child has multiple suspected triggers and you need help prioritizing testing and elimination.
- You are ready to consider a supervised food challenge to assess whether your child has outgrown the reaction.
- Your child is avoiding too many foods and you are worried about growth or nutritional adequacy.
Frequently asked
What are the most common FPIES triggers?
In infants, the most common triggers are cow's milk, soy, and grains such as rice and oats. As children get older, other foods including fish, eggs, and legumes may also trigger reactions. Each child is different, and the trigger spectrum can vary widely.
Will my child outgrow FPIES?
Many children do outgrow FPIES, particularly to common triggers like milk and soy, often by age three to five. We use supervised oral food challenges at the right time to confirm tolerance rather than keeping foods restricted indefinitely.
Ready to talk it through?
Concierge access means we have the time to listen, evaluate carefully, and stay with your family through every step.