From the Guidelines
Frequent stools in milk-fed infants are most likely caused by a milk protein allergy or intolerance, which can lead to gastrointestinal symptoms such as diarrhea and abdominal pain, as suggested by the most recent study 1. To address this:
- For breastfed infants: A 2- to 4-week trial of a maternal exclusion diet that restricts at least milk and egg is recommended, as suggested by 1 and 1.
- For formula-fed infants: Consider switching to an extensively hydrolyzed protein or amino acid–based formula, as recommended by 1 and 1. No medication is typically needed, as this is usually not a medical concern. However, if stools are watery or the infant shows signs of dehydration, consult a pediatrician immediately. This occurs because some infants may have an immune reaction to milk proteins, leading to an increase in gastrointestinal symptoms. As the infant grows and their digestive system matures, this issue often resolves on its own. Monitor the infant's weight gain and overall health. If growth is normal and the infant is not showing signs of discomfort, frequent stools in milk-fed infants are generally considered normal and not a cause for concern. Some key points to consider:
- Milk protein allergy can cause a clinical presentation that mimics gastroesophageal reflux disease (GERD) in infants, as noted in 1.
- The incidence of GERD peaks at four months of age, and rates are reportedly lower in breast-fed infants compared with formula-fed infants, as stated in 1.
- Early introduction of allergens, such as milk, may prevent the development of food allergies, as suggested by 1.
From the Research
Causes of Frequent Stools in Milk-Fed Infants
- Gastroesophageal reflux disease (GERD) is a common condition in infants, characterized by the involuntary retrograde passage of gastric contents into the esophagus, which can cause symptoms such as regurgitation, vomiting, and irritability 2.
- Cow's milk protein allergy (CMA) is another condition that can cause gastrointestinal symptoms in infants, including diarrhea, and can be associated with GERD 3, 4.
- The presentation of CMA can overlap with GERD, and both conditions may co-exist in some infants, making diagnosis challenging 2, 4.
- Lactose intolerance is not typically a cause of gastrointestinal symptoms in infants, as they have sufficient lactase to digest lactose in breast milk or formula 5.
- Other causes of frequent stools in milk-fed infants may include:
- Functional gastrointestinal disorders
- Eosinophilic esophagitis
- Anatomic abnormalities
- Metabolic and neurological diseases 4
Diagnostic Considerations
- A thorough history and physical examination are essential in establishing a clinical diagnosis of GERD or CMA in infants 2, 4.
- Warning signs such as choking, gagging, coughing with feedings, or significant irritability can indicate GERD or other diagnoses 2.
- Laboratory and radiographic investigations, such as upper gastrointestinal series, may be warranted to exclude other causes of vomiting or diarrhea 2.
- Oral food challenge, esophageal pH impedance, and endoscopy are recommended investigations for a correct clinical classification, but may not always be feasible in all infants 4.