In the small print on the side of a bottle of MiraLAX, you’ll learn that it’s recommended by the manufacturer only for people 17 years of age and older and that it should be used for no more than 7 days at a time.

But MiraLAX is given to many young children daily for months at a time – sometimes even for years.

MiraLAX and similar medications are laxatives and stool softeners using polyethylene glycol (PEG) 3350 as the active ingredient. These medicines are very widely used, work well, and are well tolerated by most children – so much so that the North American Society for Pediatric Gastroenterology, Hepatitis, and Nutrition (NASPGHAN) includes the long-term use of PEG-3350 products in its guidelines for managing pediatric constipation.

A recent pooled analysis of 18 randomized controlled studies suggests that PEG-3350 works better for childhood constipation than some other common medications and based on available evidence appears as safe as other medications.

But PEG-3350 has not been approved by the FDA for use in young children or for use by anyone for more than 7 days. The New York Times reported in early 2015 that the Food and Drug Administration has raised concerns about the use of PEG-3350 in kids, especially over the long-term:

  • We know that only minimal PEG-3350 is absorbed into the body of adults taking the medicine, but very little is known about absorption in young kids – especially those with chronic constipation or intestinal diseases.
  • PEG-3350 is available over-the-counter, so there may be little in the way of medical monitoring or oversight.
  • PEG-3350 powder is stable, but we don’t know what happens to the chemical compounds if there is a delay between mixing with water and giving a dose to a child.
  • Kids are sometimes given adult doses.
  • We don’t know enough about the safety of giving PEG-3350 for weeks or longer.
  • There have been some neuropsychiatric adverse events reported to the FDA in kids taking PEG-3350, which include “seizures, tremors, tics, headache, anxiety, lethargy, sedation, aggression, rages, obsessive-compulsive behaviors including repetitive chewing and sucking, paranoia and mood swings.” We do not know that any of these were caused by the medicine – but we’re not sure that they are not. Many kids who are referred to a pediatric gastroenterologist already have a neuropsychiatric issue before any treatment. The gut and the brain are closely connected.

The good news is that FDA has now awarded a grant to study PEG-3350 in kids to get the information we need. I’m excited about this.

In the meantime, our understanding of MiraLAX is already better than of many medicines used in kids. There is a potential for adverse effects with any medicine. With any medicine we should weigh the benefits of using it against these potential adverse effects.

Talk with your doctor about constipation – especially if it lasts longer than a week.

When practical, I’m a fan of using flaxseed as a gentle food solution for constipation. You can get Bob’s Red Mill Organic Golden Flaxseed Meal at the grocery store. I’ve seen good results with a tablespoon daily, taken with food or fluids. Or flaxseed oil for more stubborn constipation.

I also like weakly brewed Smooth Move Peppermint tea – with senna, a time-honored way to get things moving in the short run. The peppermint and fennel are added to be gentler on the tummy.

Beneficial bacteria are an important part of healthy poop. Nurture these bacteria with good food, avoid killing them from unnecessary antibiotics, and replenish them with probiotics as needed.

Often, the combination of real food, plenty to drink, and going at the first signal can help keep things on track.


  1. Cochrane Review: Osmotic and stimulant laxatives for the management of childhood constipation (Review). Evid Based Child Health. Jan 2013; 8(1):57-59.
  2. Scrutiny for Laxatives as a Childhood Remedy. The New York Times. Jan 5, 2015.
  3. FDA Drug Safety Oversight Board Meeting, June 18, 2009.

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Alan Greene MD contributor

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