What exactly is Lactose Intolerance?

What exactly is Lactose Intolerance?

Lactose intolerance is a digestive problem where the body is unable to digest lactose, which is a type of carbohydrate sugar found in milk and dairy products. Not to be confused with a CMPI (Cow’s Milk Protein Intolerance)


One of the reasons lactose intolerance is sometimes coupled with reflux is due to the symptoms of lactose intolerance sometimes causing a baby to vomit, fuss over feeding and cry in pain when they are trying to deal with wind and stomach pain. Symptoms of lactose intolerance include:

  • flatulence (wind)
  • diarrhoea
  • bloated ‘gassy’ stomach
  • stomach cramping

These symptoms usually develop within a few hours of consuming food or drink that contains lactose. The severity of symptoms and exactly when they begin depends on the amount of lactose consumed. The amount of lactose that it takes to cause symptoms will vary from child to child. For example, some may still be able to drink a small glass of milk without triggering any symptoms, while others may not even be able to tolerate a tiny drop of milk in their baby/weaning foods.

Causes of lactose intolerance

The body digests lactose using a substance called ‘lactase’ to break down lactose into two sugars called glucose and galactose, which can then be easily absorbed into the bloodstream. People with lactose intolerance don’t produce enough lactase, so lactose stays in the digestive system where it is fermented by bacteria, leading to the production of various gases, which cause the symptoms associated with lactose intolerance.

Depending on the underlying reason why the body does not produce enough lactase, lactose intolerance may be temporary or permanent. Most cases that develop in adults are inherited and tend to be lifelong, but cases in young children are often caused by an infection in the digestive system and may only last for a few weeks.

Is it the same as an allergy?

Lactose intolerance is not the same as a milk or dairy allergy. Food allergies are caused by a reaction to a food by your immune system, causing symptoms such as a rash, wheezing and itching. If you’re allergic to something, even a tiny amount can be enough to trigger a reaction, while most people with lactose intolerance can still consume small amounts of lactose without experiencing any problems (although this varies from person to person).


There is no cure for lactose intolerance, but limiting the intake of food and drink containing lactose will usually help control the symptoms. Depending on what dairy products are able to be tolerated, a child may also require additional calcium and vitamin D supplements to keep their bones strong and healthy. In some cases, your GP may refer to a paediatric dietitian for further advice on management and nutrition.

In addition to dietary changes, lactase substitutes may also be helpful. These are drops or tablets you can add to meals or drinks to improve digestion of lactose.

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