Transient Lactose Intolerance in Children

Transient lactose intolerance is a common condition in infants, although it's not serious. We'll tell you what you should know about this pathology in the following article.
Transient Lactose Intolerance in Children

Last update: 02 May, 2021

Transient lactose intolerance is a type of chronic diarrhea that occurs after acute gastroenteritis in children. It’s a relatively common condition in newborns and infants. In the following article, we’ll tell you everything you should know about this pathology.

What is lactose intolerance?

Lactose is the main sugar that’s present in cow’s milk. It’s a carbohydrate that is composed, in turn, of glucose and galactose, forming this somewhat more complex molecule.

When consuming milk, we need lactase in order for digestion to take place correctly, so we can absorb these simpler sugars. Lactase is a digestive enzyme present in the intestine and is responsible for separating glucose and galactose from lactose.

When the amount of this enzyme in our body decreases, we lose the ability to break down lactose and digest milk, which is known as lactose intolerance. It’s important to know that there are several forms of lactose intolerance, the most common of which are:

  • Age-related lactose intolerance. It occurs in most adults due to the progressive and physiological loss of lactase from our digestive system.
  • Transient lactose intolerance. We’ll discuss this pathology in more detail in this article.
A young girl pushing away a glass of milk.

Transient lactose intolerance

In the case of transient lactose intolerance, what happens is that, as the result of a viral or bacterial infection in the child, which produces an acute gastroenteritis, damage occurs in the cells of the intestine wall.

On the surface of these cells is where we find the lactase enzyme. So, if damage occurs, the action of this enzyme will be totally or partially lost. The child, therefore, will no longer be able to digest lactose correctly.

This condition mainly affects children under two years of age. What’s more, it appears approximately one week after the child suffers from gastroenteritis.

Fortunately, it’s a temporary condition. This means that, after 4 to 6 weeks, during which the cells of the intestine regenerate and regain their ability to digest, the little one can once again digest milk normally.

What are the symptoms?

The symptoms can vary greatly from one baby to another. Specifically, it’ll depend on the degree of damage to the cells of the intestine, the amount of lactase that the body’s retained, and the capacity and speed of regeneration of these cells.

Therefore, there’ll be children who show symptoms simply upon tasting any dairy product, whether milk, yogurt, cheese, etc… At the same time, there are others who present symptoms upon consuming a greater amount of these products. So, the most common symptoms of lactose intolerance are:

  • Liquid diarrhea with an acidic odor, similar to vinegar.
  • Bloating and abdominal discomfort in the child. Increased gas and severe, sharp belly pains may occur.
  • Irritation of the baby’s anus, which appears red and uncomfortable.
  • Increased sound produced by the baby’s intestines.
A baby drinking a glass of milk.

As you can expect, these symptoms will appear after the consumption of milk or dairy-containing products such as cheese, yogurt, or even some processed products such as pastries.

Diagnosis and treatment

A pediatrician usually arrives at the diagnosis simply on the basis of the infant’s symptoms. In some cases, however, additional tests are necessary. For example, these may include a stool pH test or an intestinal biopsy of the infant.

As for treatment, it’ll simply be based on removing lactose from the infant’s diet for a period of time. This is to allow rapid regeneration of the damaged intestinal cells. Then, after approximately one month, you can gradually reintroduce lactose into the child’s diet and check if the child tolerates it again.

About transient lactose intolerance…

While transient lactose intolerance is a frequent condition, it’s fortunately not very serious. Although the child will have gastrointestinal discomfort until we manage to find the diagnosis, this condition will eventually resolve itself without major consequences.

As always, it’s important that, when any symptom appears in our child, we go as soon as possible to the specialist, who will confirm the diagnosis and establish the most appropriate treatment.


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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.