A reader asks:

I saw this article regarding side effects from long term MiraLAX use in toddlers. Our doctor told us to use it for our 3 year old and we have every morning for a few months.

Any thoughts?


Miralax (polyethylene glycol or PEG) is an osmotic agent that has many medical, biological, chemical, industrial, and commercial uses. (See here for more details.) It has been used for almost two decades to treat chronic constipation in children and adults. When swallowed, PEG stays in the intestine (it’s not absorbed into the bloodstream) drawing water into the large intestine and hydrating the stool, which makes it softer and easier to pass. According to the article you refer to, there have been enough complaints over potential side effects — including neurobehavioral symptoms — to prompt a safety study from Children’s Hospital of Philadelphia.

One myth that should be debunked is that polyethylene glycol, while having some of the same characteristics, is not antifreeze. (Ethylene glycol and propylene glycol are two ingredients used in antifreeze.) One claim that is true is that Miralax has never been approved by the Food and Drug Administration to treat constipation in children. However, at the risk of creating anxiety among concerned parents, it must be said that many drugs used routinely in pediatrics have never been approved by the FDA. In other words, they are used by pediatricians and specialists “off-label.”

Most pediatricians and pediatric gastroenterologists use Miralax as a first-line medical treatment for chronic constipation when other therapies are either not helpful (the extremely picky toddler who won’t eat vegetables and other fiber) or not appropriate (some children with special health care needs, for example). We use it frequently enough because chronic constipation is rather common in the pediatric population and Miralax is rather easy to mix and administer in beverages that most kids will accept. And it works really well! Although the manufacturer’s label says Miralax shouldn’t be given for more than 7 consecutive days, many children are maintained on a daily dose for months, even years. I know in all my years of practice in pediatric primary care, I never saw symptoms that I identified as a side effect of Miralax. That’s not to say that my patients or other children who take Miralax don’t have side effects. Kids who are chronically constipated can be miserable and ornery and demonstrate other worrisome behaviors, even after treatment has started. Is this from the condition or the treatment? If one considers only the former, a diagnosis of the latter will never be made.

I’m glad researchers at CHOP are looking into the safety of Miralax. Until the study is complete, parents who give their children Miralax should be advised to talk to their pediatrician or pediatric gastroenterologist about its efficacy and safety. If Miralax is recommended to treat chronic constipation in your child and you don’t feel reassured by your doctor’s own experience of success in his or her patients, then discuss other options. (There are options, although, kids can be tricky little buggers!)

One last point: No medical intervention is benign. “What’s it going to hurt to start an antibiotic, Doc?” pediatricians hear all the time from parents looking for a quick fix to a child’s illness. “Well, plenty in some children and maybe in yours,” we might reply. It’s always a good idea to understand the condition for which you are being treated and ask questions about treatments being recommended. Understand how these treatments can help you, but also hurt you. This may require a little bit of homework. That’s what they invented Google for, right?


***Do you have a non-urgent, clinical or otherwise (but nothing personal!) question for your Pediatric Alliance doctor or provider? Send an email with your questions to palblog@pediatricalliance.com and we’ll do our best to answer them and post them on The PediaBlog. You don’t have to include your child’s name, but an idea of their age is helpful. Also, please include the name of the division you go to and your doctor’s or provider’s name.

Ask us anything! (But, please, no urgent or semi-urgent questions — we may not get to your question right away. If your child is sick, or you have acute concerns, please call our offices and speak with our triage staff.)