Lactose intolerance in children is different from food allergies. An allergy involves a histamine reaction and symptoms may include:

  • Urticaria
  • Angioedema
  • Runny nose and eyes
  • Nausea
  • Vomiting
  • Diarrhoea
  • Wheezing
  • Anaphyaxis
  • Gastro-oesophageal reflux
  • Abdominal pain
  • Constipation
  • Colic
  • Food aversion
  • Blood or mucous in stools

If your child exhibits any of the more serious symptoms, they need urgent medical treatment. This article will focus purely on lactose intolerance in children.

What is lactose intolerance?

Lactose intolerance is due to inadequate production of the enzyme lactase in the small intestine.  Lactose is a type of sugar, more accurately called a disaccharide (meaning 2 sugar molecule).

The enzyme lactase breaks this disaccharide into the monosaccharides glucose and galactose and until this is done, the sugar molecules cannot be absorbed in the small intestinal wall via the microvilli.

As you may expect, if digestion and subsequent absorption does not take place, these sugars pass through the gut, resulting in bloating, abdominal pain, wind, vomiting and/or diarrhoea. If the child has blood or slime in stools, this is NOT a symptom of intolerance and needs further investigation via a specialist.

lactose intolerance in children_2

Which children may be affected by lactose intolerance?

Any child with symptoms may be affected.  However, it is most common among people of East Asian decent, affecting 90% of the population. West African, Arab, Jewish, Greek, Italian, Hispanic and Native American populations also have a reduced ability to digest lactose.

Lactose intolerance can also occur as a result of illness or injury to the gut, for example after a bout of gastroenteritis and may be a temporary problem until the gut is healed.  This can usually take from six weeks to six months.  Lactose intolerance in infancy is very rare, but most common in Finland where it affects 1 in 60,000 babies.

What are the symptoms of lactose intolerance in children?

  • Prolonged diarrhoeal illness

  • Redness and irritation around the anus

  • Weight loss

  • Increased wind

  • Abdominal pain

  • Food avoidance

  • Vomiting

  • Crying after food

What to do if you suspect your child has lactose intolerance?

It is very important for children to gain adequate nutrients from the diet, so an initial diagnosis should be sought from your GP, rather than blindly eliminating foods. If the child is an infant, a lactose free formula may be prescribed, or lactase drops if the infant is being breastfed.

It is helpful to keep a Food Diary, detailing accurately all food and drink offered to the child along with any symptoms exhibited. A simple example of this is detailed below.

Once the child has been diagnosed, further advice and support can be gained from a BANT/CNHC registered Nutritional Therapist or a Registered Dietician. Milk and milk derivatives are in many products you may not even think of looking at, for example:

  • Breakfast cereals

  • Soups

  • Processed meats

  • Instant mashed potato

  • Baked goods

  • Ready meals

  • Cakes and biscuits and puddings

  • Pasta and pizza

  • Sauces, gravies, custards

If the intolerance was due to a viral infection, the therapist can help you heal the gut and reintroduce foods in a safe way.












WatchFit Experts change lives!

And they can do the same for you.


Pollyanna Hale Health and Lifestyle coaches
Lost 13 Kg in Total
Mel, 32y Location: London, United Kingdom Working with Pollyanna changed everything. I lost 13kg, got toned and have more energy than ever! Get same results!


Chriz Zaremba Fitness Consultant
Lost 45 Kg in Total
Chris, 50y Location: London, United Kingdom Lost 45kg after the age of 50 and now competes and wins physique competitions and runs marathons Check our weight loss plans