Lactase Deficiency in Children

Question of the Week

Q. My three year old boy had rotavirus last year. He was in the hospital for 5 Days. They told us he was a very sick little boy and it was lucky that he got better. Well, I say better because at least he is not in the hospital. Ever since then he has complained with his stomach hurting and every so often he throws up for no reason. My question is should I be concerned? His pediatrican told me he thought it was a habit for him to complain with a belly ache so often. He doesn't eat good all the time, but he is growing. I just want to be reassured that I am not overlooking something and that it is a habit or a stage. Jessica, Cleveland, GA


It is possible that it is just a behavioral issue, but it is also possible that this is being caused by a complication of his being sick with the rotavirus last year.

It is not unusual for children to develop an acquired lactase deficiency after having an episode of gastroenteritis. Since his case of rotavirus diarrhea was 'severe,' it may be even more likely.

Lactase is the enzyme that is responsible for digesting lactose, the sugar in milk and diary products. When you lose this enzyme, you can develop a lactose intolerance or malabsorption.

Symptoms of a lactose deficiency include abdominal cramping, which could explain his frequent complaints of his stomach hurting. Other symptoms can include having a lot of gas, being bloated, and having nausea and diarrhea.

Are his symptoms worse after drinking milk or eating other dairy products?

If so, then a lactase deficiency as the cause of his symptoms is even more likely.

A symptom diary, where you record what he is eating and drinking and when he has symptoms, may help you narrow down the cause of his stomach aches. A Pediatric Gastroenterologist might also be helpful in narrowing down the cause of his symptoms, and is a particularly good idea if he has very frequent symptoms and you really think that it is affecting his appetite.

It may help to temporarily take all milk and dairy products out of his diet to see if his symptoms go away, even if you aren't sure that milk is the problem. If they do or if you believe that he does have a lactase deficiency, then you can find a substitute for milk for him to drink. Good alternatives include soy milk or a lactose free milk. It is also possible to add lactase enzymes, which are available over-the-counter, to regular cow's milk or have him take a lactase enzyme tablet before drinking milk or eating other dairy products.

If he has a temporary lactase deficiency caused by his being sick with rotavirus, it may not be necessary to take all dairy products out of his diet. Some of these children can tolerate yogurt and cheese, and keeping some lactose in his diet can help him to increase his tolerance for lactose in the future. Some children with an acquired lactase deficiency can even tolerate smaller amounts of milk and don't develop symptoms until they drink more than 8 ounces or so.

Keep in mind that milk is a hidden ingredient in many foods, and if he is very sensitive to lactose, then, according to the National Institute of Diabetes and Digestive and Kidney Diseases, he may even have symptoms after eating some of these foods, including:

  • bread and other baked goods
  • processed breakfast cereals
  • instant potatoes, soups, and breakfast drinks
  • margarine
  • lunch meats (other than kosher)
  • salad dressings
  • candies and other snacks
  • mixes for pancakes, biscuits, and cookies
  • powdered meal-replacement supplements
To avoid foods with milk, be sure to read food labels and avoid those that have ingredients like milk, lactose, whey, curds, milk by-products, dry milk solids, and nonfat dry milk powder. Lactose can also be found in some prescription and over-the-counter drugs.

Keep in mind that if your child is unable to tolerate milk, then you should find other sources of calcium, like orange juice, certain vegetables, and other calcium fortified foods.

Milk and Diarrhea

Although you can sometimes develop a lactase deficiency after having a stomach virus, that doesn't mean that you can't give your kids milk and other diary products, like yogurt, when they have diarrhea. Remember that current recommendations state that you should 'feed through the diarrhea' until it gets better.

And the acidophilus in yogurt might even help the diarrhea go away faster.

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