Signs Your Child Might Be Lactose Intolerant

Written by Phong Van-Liaw, M.D., F.A.A.P. on May 18, 2016, 7:30:00 AM

There might be nothing more frustrating than knowing your child is hurting, upset or having a difficult time and not being able to pinpoint exactly what’s causing it. This is often the case at first with parents whose children are lactose intolerant, especially if the child is a newborn and can’t voice what’s wrong. The good news is that knowing what symptoms to look for may make it easier to recognize the problem early on. 

Main Causes

Normally, our bodies digest the sugars in milk with an enzyme, lactase, produced by the small intestine. Lactase turns the milk sugar into two sugars, one of which is glucose. These two sugars are then absorbed through the intestinal lining into the blood stream. People who are lactose intolerant do not produce enough lactase, meaning that the milk sugar isn’t broken down and absorbed into the bloodstream, but rather remains undigested and moves into the colon where it interacts with bacteria. It can be caused by genetics or environmental factors.


Belly Pain and Other Symptoms

If you think your child might be lactose intolerant, there are certain tell-tale symptoms that offer clues. 

If your child is an infant or a toddler, you may notice that they are fussy after feedings, and that feedings might prompt belly pain and diarrhea. If your child is a little older, look for complaints of stomach cramping, bloating, gas, diarrhea or nausea. If you suspect your child is lactose intolerant, you can tell by removing all milk products from their diet for about two weeks to see if the symptoms improve. If the symptoms improve, you can slowly add milk products back in to see if the symptoms return.


The best way to tell if your child is lactose intolerant, of course, is to talk to your pediatrician, who can administer tests to determine a diagnosis. These tests don’t need to necessarily include blood work. In fact, the most common test to determine lactose intolerance is called a hydrogen breath test, which measures hydrogen levels in the breath after a solution containing lactose is swallowed. 

How It’s Treated

There is no cure for lactose intolerance, but diet modification and supplements prescribed by your child’s pediatrician may help. They will be able to help you take lactose out of your child’s diet while not removing the calcium and vitamin D your child will need in order to thrive. Remember that lactose isn’t just found in milk, but also in foods like cheeses and bread. While there may be some trial and error at first, many children who are lactose intolerant can still eat things like hard cheeses and yogurt. Oftentimes, cow's milk can be replaced by fortified almond or soy milk in toddlers.  For infants, you can try lactose free or soy based formulas, but check with your pediatrician first to make sure these things won’t interact with allergies or other nutritional constraints your child might have.


Dr. Van-Liaw is a board-certified pediatrician who cares for patients at Kelsey-Seybold’s Fort Bend Medical and Diagnostic Center. In addition to Pediatrics, her clinical interests include Neonatal Medicine and Dermatology.



Topics: lactose intolerance in kids, lactose intolerance

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