A breastfeeding newborn passes mustard-yellow stools. What should you tell the mother?

• A. That this is normal for breastfed infants
• B. To decrease the number of feedings by two per day
• C. That the stools should be solid and pale yellow to light brown
• D. To monitor the infant for infection and, if a fever develops, to contact the pediatrician

Answer: (A)

Normal stool patterns in exclusively breastfed newborns. When a breastfed newborn passes mustard-yellow stools, that is a typical and reassuring finding. Breast milk leads to stools that are soft and loose, often bright yellow with a slightly seedy texture, and many babies stool after almost every feeding in the early weeks. This pattern reflects adequate milk intake and healthy digestion, so the best guidance is to reassure the mother that this is normal for breastfed infants. Decreasing feedings would risk inadequate nutrition and growth. Stools that are solid and pale yellow to light brown are not expected in a healthy breastfed baby and would warrant further evaluation. Signs of illness such as fever would require medical attention, but mustard-yellow stools on their own are usually nothing to worry about.