Lactose intolerance in babies: symptoms and what to do

Lactose intolerance in babies is quite rare. It can occur in premature babies or as secondary lactose intolerance after a stomach bug or another gut issue. In very rare cases, it’s inherited from both parents and present from birth. More often, it develops later, in childhood, the teens, or adulthood.

What is lactose intolerance in babies?

Lactose intolerance occurs when the body is unable to produce enough lactase, a digestive enzyme that breaks down lactose, the main sugar in milk. When a baby is unable to digest lactose, it can cause some uncomfortable symptoms.

Milk allergy vs lactose intolerance

Lactose intolerance is not the same as a milk allergy. A milk allergy is an immune reaction, whereas lactose intolerance is a problem with the digestive system.

How do I know if my baby is lactose intolerant?

Symptoms of lactose intolerance in babies can appear anywhere between 1 minute and 3 hours after drinking milk:

• Diarrhoea
• Bloated tummy
• Excessive gas
• Abdominal pain
• Vomiting
• Noisy bowel movements

None of these is fun for your little one, so they may also be unsettled and cry.

How is lactose intolerance in infants treated?

Seek advice from your baby’s GP if you suspect lactose intolerance. They will be able to help you and ensure your baby still gets all the nutrients they need.

For lactose intolerance in breastfed babies, you may be prescribed lactase drops by your GP. These will help break down the lactose in your breast milk. Lactase drops can be mixed with expressed breast milk in a sterilised bottle or given on a spoon just before you feed them. You won’t need to change your diet because the lactose in breastmilk isn’t related to how much lactose you consume yourself.

For lactose intolerance in formula-fed babies, your GP may recommend lactose-free formulas; talk to a healthcare professional for advice.

If your baby is older and eating solids, they will need to avoid foods containing lactose. Make sure you read the ingredient list on food carefully and watch out for words like whey, dry milk solids, curds, milk by-products and non-fat dry milk powder. You don’t want these.

When to seek further support

Lactose intolerance in newborns is uncommon, and with the right advice, it can be managed while keeping your baby well fed and comfortable. If you think your baby may be lactose intolerant, speak to your GP, health visitor, or healthcare professional before changing their milk, formula, or diet. They can help determine whether the symptoms are linked to lactose intolerance, a cow’s milk protein allergy, or another feeding issue.

For more guidance and tips, explore the Capricare® Parent Support Hub.