When babies have bloody stools, it’s often scary for parents. This guide from Italian pediatric experts explains food protein-induced allergic proctocolitis (FPIAP), a common food allergy in infants that causes bloody diarrhea. The experts reviewed all available research and created practical steps for doctors to diagnose and treat this condition. The main message: most cases can be diagnosed with a simple food elimination diet rather than invasive tests, and many babies outgrow this allergy. This helps families avoid unnecessary procedures while keeping babies healthy and well-nourished.

The Quick Take

  • What they studied: How doctors should diagnose and treat a food allergy in babies that causes bloody diarrhea, and what the best treatment approach is
  • Who participated: Expert pediatricians and allergy specialists from Italy who reviewed all existing research on this condition in babies and young children
  • Key finding: Most babies with this condition can be diagnosed by simply removing the problem food (usually cow’s milk) and watching if symptoms improve, rather than needing expensive or uncomfortable tests
  • What it means for you: If your baby has bloody stools, talk to your doctor about trying an elimination diet first before pursuing invasive testing. Most babies recover well and can eventually eat the problem food again as they grow older

The Research Details

This is a position paper, which means it’s not a new research study but rather a summary of all existing research on the topic. A group of expert doctors from two major Italian pediatric societies reviewed hundreds of published studies about food protein-induced allergic proctocolitis. They looked at what doctors already know about how to diagnose it, what causes it, and how to treat it.

The experts used a special process called the Delphi method to agree on recommendations. This means they discussed the evidence together multiple times until they reached agreement on the best practices. They focused on practical advice that doctors can actually use in their offices and hospitals, not just theoretical information.

The paper covers important topics like: what questions doctors should ask parents, what symptoms to look for, which tests are actually helpful, how to safely remove foods from a baby’s diet, and when babies can try eating the problem food again.

This approach is important because many doctors weren’t sure about the best way to diagnose and treat this condition. Some were ordering too many tests, and some families were unnecessarily avoiding foods for too long. By creating clear guidelines based on all available evidence, doctors can now provide better care that’s less stressful for families and better for babies’ nutrition and development.

This is a high-quality summary because it comes from respected pediatric organizations and is based on a thorough review of existing research. The experts used a structured process to make sure their recommendations were based on evidence, not just personal opinion. However, this is a summary of existing knowledge rather than a new research study, so it doesn’t provide brand new discoveries—it organizes and clarifies what we already know.

What the Results Show

The experts recommend a step-by-step approach to diagnosis. First, doctors should take a careful history from parents about when the bloody stools started, what the baby was eating, and any family history of allergies. This conversation is often the most important part of diagnosis.

Second, the recommended approach is to try removing the suspected food (usually cow’s milk protein) from the baby’s diet for 2-4 weeks and see if the symptoms improve. If the bloody stools stop, this strongly suggests a food allergy. This elimination diet is simple, safe, and doesn’t require any invasive procedures.

Third, if symptoms return when the baby eats the problem food again (called a food challenge), this confirms the diagnosis. The experts emphasize that this simple approach works well for most babies and avoids unnecessary testing. Only in complicated cases where the diagnosis is unclear should doctors order blood tests or look inside the baby’s intestines with a camera.

The paper also addresses important practical questions: What should babies eat during the elimination diet to stay healthy? The answer depends on whether the baby is breastfed or formula-fed. For breastfed babies, the mother may need to avoid the problem food. For formula-fed babies, a special hypoallergenic formula is usually recommended. The experts stress that babies need proper nutrition during this time, so families should work with doctors or nutritionists to ensure the baby is getting enough calories and nutrients.

Another key finding is about reintroduction: most babies can eventually eat the problem food again as they grow older. The experts recommend trying to reintroduce the food under medical supervision, usually after age 1-2 years, to see if the baby has outgrown the allergy. This is important because it prevents unnecessary long-term dietary restrictions.

Previous approaches to this condition were less organized, with some doctors ordering many tests and others missing the diagnosis entirely. This position paper brings together the best evidence and creates a clear pathway that most doctors can follow. It emphasizes that this condition is different from other types of food allergies—it doesn’t cause immediate reactions like hives or swelling, so the diagnosis relies more on careful observation than on allergy tests.

This paper summarizes existing knowledge rather than presenting new research data. The recommendations are based on research from many different studies, some of which may have limitations. Additionally, while the paper is from Italian experts, some recommendations may need adjustment based on different healthcare systems or populations. The paper also acknowledges that some aspects of this condition are still not completely understood, so recommendations may change as new research emerges.

The Bottom Line

If your baby has bloody stools: (1) Talk to your pediatrician about the possibility of food protein-induced allergic proctocolitis; (2) Try eliminating the suspected food (usually cow’s milk) for 2-4 weeks under medical guidance; (3) If symptoms improve, work with your doctor on a safe elimination diet that keeps your baby well-nourished; (4) Plan to reintroduce the food under medical supervision after age 1-2 years to see if your baby has outgrown the allergy. These recommendations are based on strong evidence and expert consensus (High confidence).

This information is most relevant for parents of babies under 3 years old with bloody stools or diarrhea. It’s also important for pediatricians and family doctors who care for infants. If your baby has other symptoms like severe vomiting, failure to gain weight, or signs of severe allergic reaction, additional evaluation may be needed. This guidance may not apply if your baby has other medical conditions affecting the digestive system.

Most babies show improvement in symptoms within 2-4 weeks of eliminating the problem food. Complete resolution of symptoms may take a few weeks longer. When reintroducing the food (usually after age 1-2 years), symptoms may return within hours to days if the baby is still allergic. Many babies outgrow this allergy by age 3-5 years, though some may take longer.

Want to Apply This Research?

  • Track daily stool appearance and frequency using a simple scale (normal, loose, bloody) along with foods eaten. Note any patterns between specific foods and symptoms. This creates a clear record to share with your doctor.
  • Work with your doctor to implement a structured elimination diet, removing one suspected food at a time for 2-4 weeks while tracking symptoms. Use the app to log what your baby eats and any symptoms, making it easy to see if the elimination diet is working.
  • Set monthly reminders to review symptom patterns and discuss reintroduction timing with your doctor. Track your baby’s growth and nutrition to ensure the elimination diet isn’t causing deficiencies. Plan a food reintroduction challenge with your pediatrician when appropriate, using the app to document the response.

This information is for educational purposes and should not replace professional medical advice. If your baby has bloody stools or diarrhea, consult your pediatrician for proper evaluation and diagnosis. Do not start an elimination diet without medical guidance, as improper dietary changes could affect your baby’s nutrition and development. This position paper provides general guidance; your doctor may recommend different approaches based on your baby’s individual situation, medical history, and specific symptoms. Always work with your healthcare provider before making changes to your baby’s diet.