What is lactose intolerance?

Lactose is a natural sugar found in animal milks including cow, goat and sheep’s milk. An intolerance occurs when the digestive system is unable to break down the lactose, which leads to unpleasant symptoms including diarrhoea, wind and bloating. It is estimated to affect approximately 2-5% of children. There are two types of intolerance, primary and secondary.


Primary is the most common form of intolerance and occurs when the body does not produce enough of an importance enzyme called lactase. This is responsible for breaking down lactose, so it can be absorbed and utilised by the body. It is more common in certain ethnic groups including Hispanic, African and Asian people.

Secondary intolerance is caused by the lining of the gut being damaged and it is then unable to produce enough lactase. This can occur with Crohn’s or coeliac disease.

What should you do if you suspect a lactose intolerance?

If you are concerned your child may have an intolerance to lactose, seeing a GP is the first step. They can then refer you to a gastroenterologist who may carry out a lactose intolerance test to diagnose the condition. If a positive diagnosis is identified, a referral to a dietitian is essential to ensure your child has a balanced diet with the right amount of calcium for growth and development.

What happens if lactose intolerance is confirmed?

Once diagnosed, treatment is managed through diet, and children will need to avoid foods with a high-lactose content. These are namely animal milks, soft and cottage cheeses, yogurt and fromage frais. As these foods provide calcium, protein, vitamin B12 and vitamin D, it is essential that suitable alternatives are included in the diet. These include dairy foods with reduced lactose content, such as low-lactose milk and yogurt, soya milk, cheese and yogurts, and milks made from other sources including rice, oats and almonds. Make sure you choose the milks with added calcium.

More like this

Digestives enzymes are available over the counter in liquid or capsule form. They are designed to be taken before meals containing lactose to help the body break it down. However the evidence for these is not very robust and may not be very effective for most.

You might also be interested in:

Allergies in children
Wheat allergy in children

Does your child suffer from a lactose intolerance? Leave a comment below…

This article was last reviewed on 5th February 2018.

Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.


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