A 6-month-old infant is found to have mild diarrhea accompanied by cramping at the lower abdomen after being breastfed. Based on these findings, what is the most likely cause?
• Lactose intolerance is the inability to digest lactose due to a deficiency in lactase. Secondary lactose intolerance can be caused by injury to the small intestine because the enzyme lactase is produced on the tips of the very small folds of the intestines.
• Some children become lactose intolerant after a bout of diarrhea and will need a lactose-free formula during rehydration before being returned to the usual formula or breast milk.
• Breast milk does not cause lactose intolerance, although an allergy to dairy proteins can cause a reaction in a breastfed baby.
• Primary lactose intolerance is a very rare genetic condition. With this, a baby would fail to thrive from birth and have symptoms of malabsorption and dehydration. This is a medical emergency.
• The symptoms described are not associated with kwashiorkor, celiac disease, or irritable bowel syndrome.
• Celiac disease is an autoimmune disorder caused by the wheat protein gluten.
• Irritable bowel syndrome is a set of GI symptoms from an unknown cause and is unrelated to breast milk.