Signs of Lactose Intolerance in Babies

Lactose intolerance is a result of the body's inability to digest lactose, or the sugars present in milk 2. Signs of lactose intolerance in babies manifest mainly as tummy pains and diarrhea, although some babies will experience vomiting and eczema as well. Signs of lactose intolerance usually begin about 30 to 60 minutes after consumption of dairy through formula or breast milk 2. Your pediatrician can diagnose lactose intolerance in your baby and advise on changes in her feedings.

Symptoms of Lactose Intolerance

Lactose intolerance causes stomach pain from an overproduction of gas in the intestines. Often, babies will show signs of pain after a feeding by grimacing, crying inconsolably and twisting their bodies around to relieve the discomfort. Generally, these behavioral signs are related to a feeding, but general fussiness can persist throughout the day. Babies will also have trouble sleeping more than normal. They may wake up suddenly as if in pain and start crying.

Digestion and Lactose Intolerance

Lactose intolerance shows up strongest in symptoms of the gastrointestinal system. Colic and excessive gas as well as diarrhea and spitting up or vomiting are signs of lactose intolerance in babies. According to pediatrician Dr. Sears, diarrhea in babies is different than the usual soft yellow stool. Diarrhea in babies with lactose intolerance is runny, dark in color and occurs many times during the day. Since vomiting and diarrhea can cause a baby to lose fluids, it is crucial to contact your pediatrician for advice on how to prevent dehydration.

Eczema and Lactose Intolerance

Lactose intolerance in babies can also manifest as eczema. According to Dr. Sears, eczema is characterized by dry skin with a rough texture due to small white bumps. Your baby may have dry and scaly patches or the eczema may cover large areas of his body. Flare-ups can occur, where the dry patches become red, raised and oozy. Often, these areas will be itchy and uncomfortable. Eczema can often be relieved through keeping the skin moisturized and using gentle soaps during baths.

Lactose Intolerance Versus Milk Allergies

Lactose intolerance occurs when a baby has a deficiency of the enzyme (lactase) that is needed to digest the sugar in the milk (lactose) 2. This is not a milk allergy but an intolerance to the lactose in the milk 2. A true milk allergy is the immune system's response to the protein found in the milk.


According to Dr. Stephen Wangen of the Center for Food Allergies, lactose intolerance is uncommon in babies, although it can show up temporarily in premature babies and babies who have just suffered a bout of diarrhea.