Lactose intolerance

This is a common digestive problem due to an inability to digest lactose (milk sugar). Lactose is the main sugar in milk and milk products from mammals (e.g. humans, cows, goats). Lactose is digested by the enzyme lactase in the small intestine of the gut. If lactase activity is low, undigested lactose passes into the large bowel, where it can cause symptoms of lactose intolerance. Lactose intolerance is often confused with milk allergy, but it is NOT an allergy

Common symptoms of lactose intolerance include:

  • Diarrhoea  
  • Bloating  
  • Flatulence (wind)  
  • Abdominal pain/ cramps or discomfort  
  • Stomach rumbling
  • Infantile colic 
  • Feeling sick

Primary lactose intolerance is very rare and does not usually present until after 2 years of age, usually in later childhood/ adulthood. This is due to an inherited genetic fault and runs in the families.

Secondary lactose intolerance

It can occur at any age and is usually as a result of another condition i.e. gastroenteritis, coeliac disease, inflammatory bowel disease or surgery to your small intestine or due to taking certain medications.

The secondary lactase deficiency occurs due low production of lactase enzyme.  Once the gut becomes healthy, the problem resolves.  Often you find an improvement in symptoms within 48 hours of removal of lactose from the diet.


Lactose intolerance is usually a clinical diagnosis based symptoms. Sometimes additional tests may be required in secondary care, if symptoms are persistent. There is no relationship between lactose intolerance in adult family members including the mother and in the babies.  Breast milk contains lactose (as does any mammalian milks) and decreasing the dairy content in maternal diet does not alter the amount of lactose in breast milk


  • A baby with symptoms of lactose intolerance should not necessarily be taken off the breast and fed on special lactose-free formula especially if the baby is under 6 months of age
  • Secondary lactose intolerance is temporary and usually improves as the gut heals and the initial insult is resolved. Continuing breast feed or their usual formula will not cause any harm as long as the baby is otherwise well and growing normally
  • Lactase drops such as Colief®, Care-­Co lactase infant drops can be added (as per manufacturer's instructions) to the baby's feed to make digesting the lactose easier. It is not recommended to use this beyond a week, especially if symptoms do not improve
  • If there are continued symptoms, lactose-free formula can be considered. Lactose-free formula have greater potential to cause dental caries because of the alternate sugars used in preparing the formula (glucose/corn sugar) and therefore parents must follow good dental hygiene.
  • Low lactose/lactose free formula should not be used for longer than 8 weeks without review and trial of discontinuation of treatment.  
 Note-these formulas are not suitable for milk allergy as they contain milk proteins apart from Soya Formula (wysoy) which is milk protein free

There are a few lactose-free formula available in the market:

  • Enfamil O-­Lac® - lactose, sucrose and fructose free (contains milk proteins)
  • SMA lactose-free- low lactose formula
  • Aptamil lactose-free-low lactose formula
  • SMA wysoy-Soya based formula which can be used over 6 months of age ( not recommended for under 6 months)
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