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Is Miralax Toxic for Children?

Miralax is safe but will not solve the epidemic of potty problems

My phone has been ringing nonstop since the New York Times published an article raising questions about the safety of Miralax in children.

Many, many of my patients take Miralax (PEG 3350) daily and, following my advice, have been doing so for months, even years.

So when the Times mentions “ingredients in antifreeze” and “psychiatric illness” in reference to the laxative their children are taking, naturally parents want to know: Is the medicine you prescribed poisoning my child?

The short answer: probably not, based on the available evidence. More than 100 studies have found PEG 3350 is safe to use in children, and I have found no published studies linking Miralax to severe or harmful side effects. (I discuss this research in It’s No Accident.)

Nonetheless, I welcome all inquiries into the safety of this ubiquitous laxative, and I look forward to the results of the government-funded study that will examine whether PEG 3350 may trigger psychiatric problems in children.

Still, the Times article misses the forest for the trees. While it is of course important to know whether Miralax contains trace amounts of toxins, no one is asking a more salient question: Why are so many American children constipated in the first place?

Constipation Nation

Constipation is an extremely common — I would say epidemic — problem among children in Western countries.

In a small minority of cases, constipation has a medical explanation — a child may have Hirschsprung’s disease or other rare, congenital conditions. But in 95 percent of cases, children withhold stool simply to avoid the pain of pooping. Stool piles up in the rectum, making bowel movements even larger, harder, and more painful. And the cycle continues.

This is no way a benign process. Failing to eliminate on time often leads children to develop painful, distressing, and embarrassing medical complications that needlessly cost the health-care system millions.

What’s the most common cause of abdominal pain among children seen in the emergency department? Constipation.

The most common cause of bladder and kidney infections in children? Constipation.

The most common cause of enuresis, both daytime accidents and bedwetting, in children? Constipation.

Virtually the only cause of encopresis (poop accidents) in children? Constipation.

Children are often subjected to expensive, uncomfortable tests and even surgeries that could have been prevented had the child defecated on time and completely.

Unbelievably, children also shoulder the blame for their “accidents,” because few adults realize that “rebellion” and “behavior problems” play no role here. This is a travesty. (And it’s why I wrote Bedwetting and Accidents Aren’t Your Fault.)

As I explain in It’s No Accident, the reasons children withhold stool are multiple but not complex:

•Our kids eat way too much processed food.

•Parents toilet train children too early (and without adequate follow-up), largely due to preschool deadlines.

•Dismal public-school bathroom conditions and misguided restroom policies prompt children to steer clear of the toilet.

Compounding these problems, we as a society, we ignore the early signs of constipation. No one bats an eye if a child has enormous or hard bowel movements (the top two signs of a clogged colon) or doesn’t poop at least every other day. We’re happy as long as a child goes at some point and doesn’t seem to complain.

But children need to poop every day — soft, mushy poops. When constipation goes unrecognized, stool piles up rapidly, at which point simple, drug-free therapies such as fiber and dietary changes are too little, too late.

The signs of constipation often go unrecognized, so stool piles up quickly in a child’s rectum.

The Benefits — And Limits — of Miralax

We can argue about how to fix these cultural problems until the cows come home, but a child who already is constipated needs help now, which is why Miralax is so often prescribed.

Families with Miralax on the counter are often judged harshly — “Water bottles were the tool of choice for constipation when I was a kid. Prunes also help,” wrote one Times commenter. But the reality is, no amount of water, fiber, or prune juice will dislodge a large, hard rectal clog. (Another reality: many kids who are excellent eaters end up constipated.)

So doctors typically turn to PEG 3350, which is not habit-forming and is easy to give to kids because it has no taste or odor. You can mix it in their beverages, and they typically won’t complain.

Miralax also is generally effective — more so, according to a 2014 meta-analysis, than magnesium hydroxide (Milk of Magnesia), lactulose, mineral oil, psyllium fiber, and fructose. The authors of that study concluded that is also safe, with minor side effects such as diarrhea, nausea, bloating, and vomiting.

For these reasons, I prescribe Miralax daily, but I don’t love this stuff.

While it’s effective at softening stool, PEG 3350 often does not fully clean out a child’s rectum. The rectum remains stretched and floppy, like a worn-out sock, and therefore doesn’t have the tone needed to fully evacuate or the sensation to signal to the child that it’s time to poop.

Nope, enemas aren’t habit forming! Quite the opposite — they are important for shrinking a stretched-out rectum back to size.

Only a completely cleaned-out rectum can bounce back sufficiently, which is why I typically prescribe enemas for my severely constipated patients. Enemas have been proven in rigorous studies to resolve enuresis and encopresis, and yes, enemas are safe for children. On the whole, my patients who receive enemas get far better results than those who use Miralax.

The problem: Most parents simply won’t give their constipated children enemas, insisting the child will refuse. (My experience demonstrates otherwise; it’s parents who project their fears on their kids.)

Even many pediatricians won’t go near enemas. One doctor told a patient of mine that enemas are “cruel and unusual punishment.” That’s a travesty, too.

So, I end up prescribing Miralax all the time. And while it’s not as effective as enemas, it does an OK job.

“But Miralax Isn’t Natural”

Many folks object to Miralax on the grounds that it’s “not natural.” That’s absolutely true, and I wish I never had to prescribe it. However, carrying around a rectum full of poop throughout an entire childhood, a common scenario these days, is not natural either and can have serious, long-term consequences.

Also not natural: walking around with a tube inserted through your abdomen into your colon so you can flush out poop with liquid laxatives. Yet that scenario, known as a cecostomy, is becoming more common in children whose severe constipation has gone untreated for years.

Getting a constipated child cleaned out is critical, and laxatives can be an effective approach. As one of my colleagues, a pediatric gastroenterologist, told me, “Parents are terrified of the consequences of giving their kids laxatives, but what about the consequences of taking out part of a 6-year-old’s colon? Many people don’t realize how severe the cost of undermanagement can be.”

This doctor has performed more than 100 cecostomies in children whose stretched-out colons are permanently damaged from constipation and has sent more than a handful handful of his worst-case patients to surgeons for colostomies.

I do not think that parents should stop giving their children Miralax just because small amounts of toxins were discovered in eight samples in 2008. At the same time, I urge parents and pediatricians to give enemas a second look.

Ultimately, it doesn’t matter what method is used to empty a child’s clogged rectum (as long as that method doesn’t harm the child, of course). What does matter is that the child’s bowels empty completely on daily basis, so the kid don’t show up at the ER with painful urinary tract infections or opt out of sleep-away camp because she wets the bed.

I hope the harsh light shined on Miralax will help illuminate our nation’s epidemic of pediatric constipation, leading to preventive strategies, more rapid diagnoses, and more effective treatment for these kids.

Perhaps then we’ll all need less Miralax.

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