Could Your Toddler Be Lactose Intolerant?

toddler milk

At the ripe old age of 30, I discovered that I was actually lactose intolerant. With that seemingly simple realization, I suddenly looked back on a lifetime of memories through new eyes. All those times in my childhood that I had complained about my stomach hurting? All the nights I had driven home from my boyfriend's house, miserable from the bloating I had tried to hide in my stomach all evening? All the bowls and bowls of cereal I had eaten, never realizing they were the culprit?

I realized how much different my life could have been if I had realized that I was lactose intolerant, or if my parents had recognized the relevance of my signs and symptoms. Now, as a parent myself, I've been especially careful to look out for any signs and symptoms of lactose intolerance in my own children as early as possible.

Toddlerhood is a time when many signs of lactose intolerance can present themselves, as many parents start to introduce milk to their children. If you are wondering if your toddler could be lactose intolerant, here are some things to look for.

What Is Lactose Intolerance?

Lactose intolerance occurs when the body is not able to properly break down lactose. Lactose is a sugar and it requires a specific amount of an enzyme, called lactase, which is present in the lining of the intestine, to be digested.

When children are about two years old, their bodies produce less lactase. Because of this, signs of lactose intolerance may begin during the toddler years.

Two years old is also when the body starts to produce less lactase, the enzyme needed to break down lactose, so signs of lactose intolerance may be especially evident in the toddler years.

Signs of Lactose Intolerance in Toddlers

The most common signs of lactose intolerance are:

  • Diarrhea
  • Gas
  • Bloating
  • Cramps
  • Nausea
  • Stomach pain

The signs and symptoms of lactose intolerance can be difficult to recognize in toddlers—a two-year-old can't exactly tell you that she's feeling bloated. 

Instead, it's most helpful to track your child's diet and symptoms following eating dairy. Make a special point to look out for the following:

  • Loose, foul-smelling stools: It's hard to explain, but the stools can smell sickly sweet and almost fermented (it's gross, I know), which actually makes a lot of sense when you think about it—if your toddler is lactose intolerant, the sugar from the lactose isn't being broken down properly, so it literally ferments (is digested by bacteria) in the large intestine instead.
  • Crying or irritability after eating dairy: Your child may not be able to vocalize that he or she is having stomach discomfort after eating, but their behavior may be a sign. Is your toddler more clingy, whiny, or otherwise just not themself after eating dairy? You can also physically observe his stomach to check for bloating. Those toddler tummies can be hard to see, but bloating can make itself pretty visible.

How to Test for Lactose Intolerance

Testing for lactose intolerance in a toddler may depend on your pediatrician's preference. Some may diagnose the lactose intolerance based on symptoms alone, and more specifically if those symptoms improve when you remove dairy from your toddler's diet, while others may request that your toddler have some testing done.

The American Academy of Pediatrics recommends that noninvasive hydrogen breath testing or an invasive intestinal biopsy to more definitively diagnose lactose intolerance in children and adolescents.

Living With Lactose Intolerance

If your toddler does have lactose intolerance, you will have to move forward with offering less dairy in their diets. The good news is that there are more dairy-free options for snacks and meals than ever, so you will have plenty of menu items at your disposal (ice cream is totally still on the table!).

In addition, many people who are lactose intolerant can take over the counter lactase supplements, such as Lactaid, in chewable or pill or form, which can alleviate symptoms and enable more normal digestion of dairy.

In more severe cases of lactose intolerance, doctors may recommend a child avoid lactose entirely, so consult your child's pediatrician first.

It's also important to realize that lactose intolerance is not an exact science; your toddler may be able to handle a small amount of cheese, for example, or one glass of milk, but not more than that.

It's helpful to first eliminate dairy completely from your child's diet, to allow his or her system to fully rid itself of the lactose and then slowly reintroduce specific types of dairy, one at a time.

You can also get familiar with common types of high and low-lactase foods. Milk can have about 5 to 8 grams of lactase per glass, while a serving of butter has a lower amount of lactase.

Living with lactose intolerance is very doable, but it is important to make sure that your child gets adequate calcium and vitamin D in their diet. The good news is, like traditional dairy products, most soy and almond milk are fortified.

2 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Heyman MB. Lactose Intolerance in Infants, Children, and Adolescents. Pediatrics. 2006;118(3):1279-1286. doi:10.1542/peds.2006-172

  2. Porto A. Lactose Intolerance in Infants & Children: Parent FAQs. American Academy of Pediatrics. Updated September 29, 2019.

By Chaunie Brusie, RN
Chaunie Brusie is a registered nurse with experience in long-term, critical care, and obstetrical and pediatric nursing.