Most babies normally digest milk without complication, so if you notice that your baby consistently develops diarrhea from milk, you need to talk with your pediatrician. Lactose intolerance is very rare in babies, but could develop if your baby is premature, has a digestive infection or has recently had surgery. It is more likely that your baby has milk protein intolerance or a milk allergy.
Lactose Intolerance Consideration
During the third trimester, the fetus begins to produce lactase, the enzyme needed to digest lactose, the sugar found all forms of milk, including breast milk. If your baby is born premature, her intestines may not be producing lactase, but should begin around her expected due date. Lactose intolerance is common in adulthood but is very rare before a child is two years old. Lactose intolerance in babies will cause diarrhea, gas, bloating, fussiness and foul-smelling stools.
Milk Protein Intolerance
Milk protein intolerance is a condition commonly found in babies that could cause diarrhea after drinking milk. Milk protein intolerance is related to cow's milk and is not caused by breast milk. Milk contains whey and casein proteins that may be difficulty for your baby's digestive system to digest. Milk protein intolerance in babies will cause the baby to vomit, develop diarrhea and experience pain in the stomach. If your baby is bottle-fed your doctor may recommend using a soy-based infant formula.
Milk Allergy
A milk allergy is a common food-related condition affecting children under the age of five years old. Milk allergies are more identifiable than intolerances because milk allergies cause symptoms to develop in other places beside the digestive system. Milk allergies will cause hives, asthma, nasal congestion and skin itchiness, whereas intolerances will not. A milk allergy is related to cow's milk. Breast milk will not cause a milk allergy, unless the mother is drinking cow's milk. Babies with a milk allergy will have to avoid the consumption of all dairy products.
Food Poisoning
It is possible that your baby has food poisoning from milk that has gone sour. If you notice that your baby developed diarrhea recently and it is an isolated instance, talk with your doctor about the possibility of food poisoning. Food poisoning can cause vomiting, diarrhea, fever, chills and sleepiness in infants.
