Blood in Baby Stool and Food Allergies

Dietary protein proctitis

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An infant with bloody stools can be very concerning, especially when this occurs during the first few months of life. While there are a number of serious causes of bloody stools in infants, other causes may not be quite so dangerous. Is it possible that bloody stools are caused by food allergies? Surprisingly, the answer is yes. Dietary protein proctitis is a form of non-allergic food protein intolerance that occurs in young infants, most often in those who are exclusively breastfed.

Dietary protein proctitis is a very mild form of food protein-induced enterocolitis (FPIES) that affects young infants but causes only blood-streaked stools that are otherwise normal to slightly soft in consistency. Unlike FPIES, affected infants are otherwise well, have no vomiting, diarrhea, trouble gaining weight or other concerning symptoms. Most infants with dietary protein proctitis have symptoms during the first 2 months of life, and most are breastfed only (unlike FPIES, which usually occurs in infants who are formula-fed). Usually, the cow's milk protein is the cause of the symptoms, which may be from baby formula or from breast milk as a result of mother’s diet.

Allergy testing for milk or other foods is negative in infants with dietary protein proctitis since the reaction is not truly a food allergy, but food intolerance. Most infants have similar symptoms with soy formulas, so extensively hydrolyzed formulas are recommended instead.

The bloody stools usually go away within a few days after milk and soy proteins are removed from the infant's diet. Most infants can resume eating milk and soy proteins after 1 year of age since dietary protein proctitis usually resolves by that time.

Learn more about allergy to infant formulas.


Lake AM. Food-Induced Eosinophilic Proctocolitis. J Pediatr Gastro Nutr. 2000;30:S58-60.

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