The truth about Miralax in children

Parents are appropriately expressing concern about the safety of Miralax®, a commonly used stool softener in kids, after a recent New York Times article exposed a potential association with long-term use of the drug and undesired behavioral side effects. As the article explains, the FDA has awarded a research grant to a team at the Children’s Hospital of Philadelphia (CHOP) to directly address these concerns.

Miralax® has been used in the fight against chronic constipation in children of all ages for years. The active ingredient in Miralax® is polyethylene glycol 3350 (PEG 3350). PEG 3350 is a very large polymer that is too big to be absorbed by the intestine. When PEG 3350 is consumed, it stays in the gut and holds water. This makes the poop within the gut soft and easy to pass, gently relieving constipation. PEG 3350 does not work on the muscles or nerves of the gut so it not habit forming, nor does it cause a dependance on the product.

It is important to know that PEG 3350 has been extensively studied for effectiveness in chronic constipation. These studies have included the medication being used in various ages, different doses, and for many types of stooling problems. In addition, no significant effects from long-term use of the medication have been reported in pediatric gastroenterology literature.

PEG 3350 itself, however, is not the entire focus of concern for the FDA. This new research will also focus on bi-products of PEG 3350, specifically ethylene glycol (EG) and diethylene glycol (DEG). Both EG and DEG are known to be found in trace amounts in manufactured PEG-containing laxatives. Presence of these trace bi-products are approved by the FDA; also being found in various manufactured household items including cosmetics, medications, ink pens, and toothpaste.

Trace amounts of EG and DEG can be safely eliminated from your body. The chemicals are changed to metabolites in the liver and eliminated via your kidneys. (In other words, you pee it out.) However, large amounts of these chemicals are clearly unsafe and known to be toxic to humans and animals.

So, what should parents using Miralax® do now?

1. Know that examining Miralax® for long-term safety is a good thing. I think parents can agree, myself included, that additional studies ensuring the safety of this medication will bring needed confirmation and reassurance that Miralax® can remain in our home medicine cabinets.

2. With what is currently known, I have no reservations about my patients with severe constipation continuing to use the lowest-effective dose of Miralax® as part of their treatment plan. Chronic constipation is a significant medical issue. For many children, behavior modification and dietary changes are simply not enough to create positive change, and Miralax® is critical to achieve comfort and success. It is important to understand that completely stopping Miralax® may lead to greater harm, as children with untreated constipation can develop significant problems like severe pain, blockages, and bleeding.

3. For mild constipation, there are alternatives. Natural, fiber-containing foods, routine exercise, and lots of water are ideal components to stool regularity. Consistency with this plan, however, is often difficult to maintain. Mineral oil, laculose, and fiber supplements (solutions, gummies, bars, etc.) are alternatives that have also been used to control mild constipation. These alternatives have varying amounts of effectiveness, and each have potential side effects. Discuss with your doctor if you are considering one of these alternatives to ensure the correct plan for your child. Of critical importance is the alternative you choose must continue to help keep your child’s stools soft and regular. Be sure to monitor stool patterns to ensure any change is successful.

Bottom line: Current research supports the effective use of Miralax® for severe constipation. We will anticipate new research in the future. Meanwhile, use of the product at its lowest effective dose continues to be recommended.

For more information about constipation and its remedies, explore the NIDDK website or

Thanks to Dr. Kelsey Ragsdale for compiling much of the information used in this post.

Natasha Burgert is a pediatrician who blogs at KC Kids Doc.

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