Lactose intolerance is caused when the milk sugar, lactose, cannot be digested and absorbed. You’ll find lactose is found in breast-milk as well as dairy products. The symptoms of lactose intolerance include abdominal pain, abdominal swelling, flatulence and diarrhea.
Some parents can confuse the symptoms of lactose intolerance with milk allergy. Whilst the two conditions share similar symptoms, lactose intolerance is a digestive problem, whereas milk allergy involves the immune system. So, whilst lactose intolerance can cause a great deal of discomfort, it will not produce a life-threatening reaction such as anaphylaxis.
Lactose intolerance is quite common in adults as many people gradually lose the ability to digest lactose over their lifetime. This usually develops after the age of three and can be lifelong. In infants though, lactose intolerance has one of two underlying causes. The first cause is called primary lactose intolerance and happens when no lactase enzymes are made at all. This is a rare genetic condition and a baby with this condition needs a special diet from the first day of life.
The most common type of lactose intolerance found in infants is called secondary lactose intolerance. The cause is mostly from damage to the gut lining, which affects the production of the lactase enzyme. In this situation, the infant still has the ability to make lactase, but its production is temporarily blunted. Causes of gut damage can include:
- Food intolerance or allergy
- Parasitic infection such as giardiasis or cryptosporidiosis
- Coeliac disease
- Following bowel surgery.
Managing lactose intolerance
The good news is that secondary lactose intolerance is temporary, as long as the gut damage can heal. For example, removing an allergic food from the mother’s diet allows the gut to heal. During the period of lactose intolerance, breastfeeding can normally still continue if the baby is otherwise well. Sometimes the use of a lactose-free formula for several weeks is recommended, with the gradual shift back to breast milk or a standard infant formula once the symptoms of lactose intolerance have resolved.
If the baby has moved to solids when lactose intolerance appears, it is important to remove foods high in milk such as yoghurt, soft cheese and custard. Hard cheeses such as cheddar are normally okay as they have a low content of lactose. A normal diet with lactose-containing foods can usually be reintroduced once the gut damage has resolved.
Sometimes the addition of the enzyme lactase as a supplement to babies who have symptoms of lactose intolerance can help. In this case, the added lactase helps to support the body to digest the lactose found in breast milk when the infant’s own internal supply is compromised.