Is Miralax Safe for Children?

Up to about 30% of kids experience constipation. And when kids are constipated they can get irritable, frustrated, and generally unhappy. When diet and physical activity changes don’t seem to be doing the trick, you may turn to medications to help relieve your child’s constipation.

Miralax (polyethylene glycol), an over-the-counter (OTC) laxative, has been helping kids with constipation for years. Healthcare professionals (HCPs) and parents like it because it’s easy for kids to take, it doesn’t have many side effects, and it works quickly. But there have been some reports saying it may be causing more harm than good. Here’s what you should know.

Is Miralax safe for kids?

There are mixed opinions about whether or not Miralax is safe for constipation in kids. HCPs say it’s safe and are still recommending it for children. And experts rank it as a first-choice treatment for constipation in children based on multiple studies.

One study from 2003 showed that Miralax was safe in 83 children with long-term constipation who took the medication for about 9 months. And according to the American Academy of Pediatrics, the latest evidence shows that Miralax is safe in babies, toddlers, children, and adults.

Even so, there are parents who believe Miralax can cause unexpected behavior-related side effects in kids, such as mood swings and aggression. This has prompted the FDA to take a second look at the safety of Miralax. In fact, they funded a study in 2014, which is expected to be completed at the end of 2024.

The study intends to see if certain substances that may be contributing to these behaviors are present in children taking Miralax. This is the first step in determining whether there’s a link between these side effects and the medication. But in the meantime, some parents may choose to avoid Miralax.

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Who can take Miralax?

The label on Miralax says it's for anyone age 17 and older, but to check with your child’s pediatrician before using it in kids and adolescents age 16 and younger. This means it may be recommended off-label for this age group. Off-label means it’s being used in a way that hasn’t been approved by the FDA.

How does Miralax work for kids?

So, how does Miralax work? The main ingredient in Miralax is polyethylene glycol 3350, or, PEG for short. PEG is an osmotic laxative that helps relieve constipation by making stool softer and easier to pass. It does this by helping the digestive tract hold more water, which also pulls more water into the stool.

Miralax comes as a powder that you mix with drinks like water or juice before drinking. It also comes with an easy-to-use measuring cap marked to help adults get the right dose. Kids, however, may need a different dose. 

Your healthcare team will tell you what dose to use for your child and how often you should give Miralax. It usually takes 1 to 3 days for Miralax to start working. If it seems like Miralax is not working, your healthcare team may need to adjust the dose.

Are there any serious side effects of Miralax for kids?

Miralax can cause some side effects. They’re mostly abdominal-related and include:

• Bloating

• Stomach cramping

• Gas

• Nausea

EXPERT PICKS: WHAT TO READ NEXT

• Laxatives for kids: Experts break down which over-the-counter laxatives are safe for kids.

• Home remedies for constipation: Besides medications, there are other things you can try to help relieve your child’s constipation. Here’s a list of natural constipation remedies for kids to consider.

• Miralax side effects: Miralax works well to relieve constipation, but side effects are possible. Learn more about potential Miralax side effects — from nausea to gas and bloating.

Behavior-related side effects have also been reported in children taking Miralax. Examples of these include:

• Anxiety

• Depression

• Mood swings

• Anger

• Abnormal behavior

• Nervousness

As mentioned above, an FDA study is looking into whether Miralax is causing these behavioral side effects, or if there’s another reason. For example, it’s possible that these behaviors are actually caused by constipation itself or medical conditions that lead to constipation. But as of right now, there’s no definitive evidence that Miralax is the cause.

What are some alternatives to Miralax for kids?

If Miralax doesn’t sound like the right choice for your child, there are other things you can try to get things moving. Remember, Miralax works by adding more water to the stool and digestive tract. Making sure your child is getting enough water to drink is an important first step.

Diet

The foods that your child is eating can also cause constipation. A few examples of foods that might be making things worse include:

• Chips

• Fast food

• Meat

• Processed foods

There are also foods that can help improve constipation. If your child has chronic constipation, increasing the amount of fiber in their diet is typically the first treatment option. Examples of foods that are good sources of fiber include:

• Pears

• Apples

• Oatmeal

• Lentils

• Carrots

In general, children between 1 to 3 years old should be getting 19 grams of fiber every day. And children ages 4 to 8 years old should be getting 25 grams. Talk to your child’s pediatrician about the right amount of fiber for your child.

Physical activity

Physical activity is also important for keeping regular bowel habits. Make sure your child is getting enough movement every day. Limit the amount of screen time and suggest alternative activities that will keep your child more active. There are many fun ways to encourage your child to get enough physical activity each day:

• Make it a family activity. Go for walks or bike rides together.

• Make it fun. Take your child to their favorite park or play outside games, like tag or jump rope.

• Enroll them in activities. Sign your child up for activities in the community, such as sports teams, dance class, or martial arts.

• Involve them in active chores. Ask your child to help wash the car, rake the lawn, or mop the floor.

Toilet routine

If your child has constipation from withholding stool, try to set up a toilet schedule. This can help kids get into a healthy rhythm so they don’t continue to hold back their stool.

Another recommendation from pediatricians is to improve toilet posture. Good posture on the toilet is important and can help make passing stool easier for your child. Potty stools can help get your child in the right position.

Minimize stress

Studies show that stress can negatively affect bowel function and lead to constipation. Some examples of stress are anxiety, trouble sleeping, and distressing events. A few ways you can help your child reduce stress are:

• Help them get enough sleep each night

• Introduce mindfulness activities, like coloring

• Teach them deep-breathing exercises

• Ask them regularly if there is anything troubling them

Other medications

If these natural options don’t work, Milk of Magnesia (magnesium hydroxide) or mineral oil are examples of other laxatives and stool softeners that can be used in children.

Neither of these medications has FDA approval for use in children long term. They also cause some unpleasant side effects — like bloating, gas, and stomach pain. Young children can associate this stomach pain with using the bathroom and withhold their stool even more. These options also don’t taste very good, so getting kids to take them isn’t easy.

Make sure you check in with your child’s pediatrician if you’ve been giving your child a medication for constipation for more than 1 week.

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Written by:

Rebecca Liggon, PharmD

Rebecca Liggon is a clinical pharmacist in Madison, Wisconsin. She holds a bachelor’s degree in pharmacy from the University of Wisconsin-Madison and a doctorate degree in pharmacy from the University of Colorado Health Sciences Center.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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