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The Straight Poop on Constipation

By March 13, 2017 No Comments

Once you become a parent, you spend way too much time thinking about poop. When did the baby poop?  How much did they poop?  What was the color, what was the consistency?  While you might find yourself obsessing over your child’s bowels a little less as they become toddlers and preschoolers, you will still likely spend way more time than you ever imagined thinking about your kid’s poop. Most of these thoughts will be focused on one issue: Is my child constipated?

As a pediatrician I regularly see parents that are worried that their child is constipated (also because I’m a pediatrician I can *get away with saying “poop” instead of “bowel movements” or “stool” here). Some pediatricians would argue that all kids are constipated, but the data doesn’t support that claim, as the prevalence is somewhere between 1% and 36%.

So why, as parents, are we so worried about constipation? Well, there are a lot of reasons. Most of us have been constipated at some point in our lives and we know how uncomfortable, and sometimes painful, it can be. We also don’t want to see our kids in discomfort or pain, especially if we can avoid it. Constipation can delay your child’s ability to potty train, lead to UTIs and chronic constipation can create a significant disruption in the family.

Today, we’re going to talk about constipation, but before we can talk about that, we need to talk about what poop is and how it’s made.

What is Poop?
Most of us think that poop is undigested food, but that’s not completely accurate. Poop is actually 75% water, 21-23% what we consider “organic solids” and the remaining 2-4% is dead skin and blood cells, mucous, intestinal secretions and minerals. Digested (and undigested) food falls into the category of organic solids, but even then, it’s a fairly small proportion of it. Up to 55% of the organic solids in our poop can be composed of what we call bacterial biomass, which are dead bacteria that normally live in our digestive tract.

How Poop is Made
Most of us are very familiar with the first steps in the digestive system: chewing and swallowing. From there, the food we’ve eaten and fluids we’ve drank wind up in the stomach, where digestive juices help break the food and drink down. The food and digestive juices are then released into the small intestines where more enzymes are released from the pancreas and liver. The walls of the small intestines absorb the nutrients in the food and fluid and contract to push the remainder through the system.

The next stop in the GI tract is where acute constipation develops: the large intestine (AKA: the colon). The large intestine absorbs fluids (and any remaining nutrients) from the food. It’s this absorption of water that helps poop take on a more solid form, but if our colon absorbs too much water, stools can become hard and difficult to pass. The final stop for our poop is the rectum, where it’s held until released (also known as “pooping”).

What’s Constipation?
Your child is considered constipated when they have infrequent bowel movements that are often large, dry, hard and painful.  These poops can be so large that they clog the toilet, they can also take a long time to pass due to their size. Some people think that any poop that isn’t soft qualifies as constipation, but that’s not an accurate use of the term. It is unfortunately common to see streaks of bright red blood in the poop * of a constipated child. This is usually because the poop is so large and hard, that the walls of the anus actually tear as the poop is pushed out.

There are also different types of constipation. The most common is what we call functional (or idiopathic) constipation, which is the type of constipation we’re discussing here. Constipation can be a tricky subject so I spoke with Dr. Matthew Riley of Northwest Pediatric Gastroenterology in Portland, Oregon to help out with this section. Dr. Riley says that “90% of kids with constipation all suffer from the same problem: functional constipation.  This just means that their constipation is not caused by a bowel obstruction, nerve problem, issue with how their colon is formed or some other exotic disease”.

For kids in particular, having a painful poop can cause fear of pooping which often leads to holding their poop in and even more constipation.  It becomes a vicious cycle.  This is one of the reasons that constipation is so common during potty training.  Many potty training kids want to keep some control during the process so they hold their poop in which contributes to this cycle. Constipation can also lead to fecal incontinence and set the potty training process back.

What Causes Constipation?
Dr. Riley says there are a few reasons why kids can become constipated, “Kids can become constipated because their colon is doing an exceptional job at conserving water (this is called slow transit constipation). They can become constipated because they’re just not very good at pooping yet (this is called functional outlet obstruction). They can also become constipated because their diet is low in foods that help us poop. Some children become constipated due to a combination of two or three of these factors”.

In my general pediatrics practice, I most frequently see functional constipation because patients have a fairly constipating diet (high in starch, protein and dairy but low in fiber) or they don’t drink enough water during the day. If you’ve told your parents that your child is constipated chances are they’ve told you that you need to make sure they get more “roughage” in their diet.   It turns out your parents are right about this one. “Roughage” also known as dietary fiber, is crucial to keeping your child’s poop moving (literally). Our bodies can’t break down some of the things we eat, and dietary fiber is one of them. If your diet is low in fiber, that means your body is absorbing a lot of what you eat, and there isn’t much left over to form poop. Fiber is also *osmotic, meaning that it attracts water, which makes the poop softer and easier to pass.

How Can I Tell if My Child is Constipated?
The symptoms of constipation aren’t always obvious. The most common way I find constipation in my practice is during a visit for stomach aches.  Children suffering from constipation will usually have stomach aches during or right after eating, because when we eat our GI tract starts moving to digest and make room for the new food.  If a large amount of poop is hanging out in the colon, it’s going to hurt when the colon starts squeezing against it.  Usually the pain is low down on the left side of the abdomen, which is where poop hangs out before it leaves the body.  Children can also present with other signs of constipation.  Dr. Riley says parents should look for these symptoms:

  • Poops less than 3-4 times per week
  • Poop that is hard, large or painful
  • Your child avoids pooping or seems to spend a long time trying to poop
  • Your child has accidents (soiling), or has poop in the underpants (One of the sneakiest ways constipation will show itself)

Another common symptom of constipation has nothing to do with the GI tract but with the urinary tract.  Because a large amount of built up poop can press on the bladder, some kids present with urinary accidents or even urinary tract infections.  Therefore, it’s important to recognize constipation in order to prevent these complications.

How Is Constipation Treated?
The main way to treat functional constipation is to improve the function.  This includes increasing the child’s intake of clear fluids and dietary fiber, and ensuring that they have access to a toilet whenever they feel the urge to go.   Foods that are high in fiber include fruits, vegetables, dried fruits (including prunes, raisins and dates), oatmeal, whole wheat pastas, bran and beans. If your child is a picky eater this may be mission impossible, so you may need to turn to an osmotic laxative, which Dr. Riley explains below.

In more severe cases, Dr. Riley recommends first ensuring the child’s colon is not impacted with an excessive amount of stool. This may require a special “clean out” either at home or in the hospital, which for most children may include an osmotic laxative. Just like dietary fiber, osmotic laxatives attract water, says Dr. Riley. “These are medicines which help keep more water in the poop, so that the poop is softer and easier to pass.  Common osmotic laxatives are milk of magnesia, lactulose and polyethylene glycol 3350 (commonly sold as Miralax or Glycolax).”

Children also need to be encouraged to go to the bathroom as soon as they feel the urge.  I even recommend that parents offer small rewards or a sticker on a chart when younger kids go to the bathroom on their own. “Children need to make an effort to sit on the toilet after mealtimes” as well according to Dr. Riley.  Sometimes a trip to the pediatric GI is necessary to talk about “how to properly use the muscles of the belly and the bottom to pass a bowel movement”.

Is Miralax Safe to Use Regularly?
There has been a lot of controversy over Miralax lately, which was addressed by a pharmacist in an earlier post on, But I’ll let Dr. Riley take it from here:

“Miralax is the original name for prescription polyethylene glycol 3350 (PEG 3350) powder.  It was approved by the FDA in 1999 for use in adults.  However, the actual medicine has been in use longer than that in other forms.  The safety data for Miralax is incredibly good.  It is so good and so effective that it is one of the most popular laxatives currently used in the United States.  It is now available over the counter and as a generic.

“When Miralax first became widely used, people associated PEG 3350 with another chemical called ethylene glycol, which is the poisonous ingredient in car anti-freeze! I can assure you that that their chemical compounds are different.

“Because Miralax was so effective as a laxative, it was immediately used “off-label” by doctors caring for children.  This just means that the use of Miralax in children was not part of the original studies sent to the FDA.  However, I think it would be very hard to find a pediatrician or pediatric gastroenterologist who hasn’t prescribed it and had success treating patients with it. Also, we have over 16 years of extensive clinical experience using it with very few serious adverse effects noticed.

“The FDA has just funded a major study at the Children’s Hospital of Philadelphia to do more specific studies on the effect of Miralax in children.  We are not expecting any major problems, but as pediatricians we always want to make sure our treatments and medicines are not having even small effects on our smallest patients.”

Constipation is no fun no matter how old you are. As always, if you think your child is constipated make sure your first stop is to your doctor to make sure that something more complicated isn’t going on. And that’s the straight poop on constipation (sorry, I couldn’t resist).

Categories: Food, Nutrition, + Infant Feeding, Science 101 + Mythbusting

Should Parents Be Concerned About Miralax?

By February 27, 2017 1 Comment

Last week we received a number of questions about a statement released by a group of parents of children with disparate neuropsychological issues.  The parents claimed that their children’s symptoms began after they began taking the over the counter laxative Miralax (polyethylene glycol 3350), and that the medication was at fault.  Miralax is approved only for use in those age 17 or above, and the parents have expressed concern that they were instructed to give their children the laxative not approved for use in their age group.

This was cause for concern for many parents, especially those whose children have dealt with constipation.  To answer our reader questions we reached out to François Lavallée, a pharmacist in the province of Quebec, Canada and who is also the father of two young children. Matthew Hartings, a professor of chemistry at American University in Washington, DC (and a dad as well), helped out with some of the chemistry.

We have received a number of questions from concerned parents about this story. Thank you for taking time out of your schedule to speak with me.
I can see why parents would be concerned. I’m a parent myself and nobody wants to put their kids at unnecessary risk. I don’t doubt that the children of the parents coming forward have neuropsychological issues. When you are the parent to a child with neuropsychological issues, depending on the severity, it is very hard both physically and emotionally. I think what they are doing is noble because they want to prevent other children from experiencing something similar, but I’m not sure that the chemical component in Miralax, polyethelyne glycol (PEG) 3350, is what has caused the symptoms they are describing.

Right now the symptoms that are being disclosed publicly by the parents are a little vague, and aren’t consistent with each other. Some describe, the development of aggression and paranoia, others describe motor issues such as tics. Usually when symptoms are caused by something children are exposed to there’s an identifiable pattern. It would be so simple if it were the case here, we could just ban that substance and be done with it.

In reality, considering the diverse symptoms reported at this time there is probably more than one cause. What makes it more difficult is that in some cases the individuals are now adults and are claiming the exposure as toddlers caused their symptoms. It is incredibly difficult to pinpoint a cause ten or fifteen years after the onset of symptoms. There may have genetic predispositions to some of these issues or the symptoms may have been acquired through another exposure through food, air, water or other drugs.

I think parents need to exercise caution when they read things like this online. These articles often lead with really shocking information that’s completely out of context. The important context is usually at the bottom, but they know that most people don’t read articles all the way through. These websites prey on parents’ fears for clicks, and can cause them to panic when they don’t have to.

I think part of what makes this so shocking is the claim that the same chemical that’s in anti-freeze is also in a laxative that parents have been giving their children. Can you tell me a little more about PEG 3350 and antifreeze?
First it’s important to know that this is not the same chemical that’s in antifreeze, but it is easy to confuse the two. Their names sound very similar.  A number of the articles have confused the two chemicals which is why I really think parents need to exercise caution when reading things like this online.

Ethylene glycol is the chemical that is in antifreeze, it is highly toxic and we see kids sometimes ingest it accidentally if it’s in the garage or not properly secured because it has a sweet taste to it. Polyethylene glycol or PEG, starts with “poly”, a prefix meaning “many” or “multiple”. In this case, it means many ethylene glycol molecules linked together, which makes it a different chemical, with different properties.  As you can see here, the two chemicals have the same basic ingredient, simply repeated “n” times in the case of PEG:

Ethylene glycol: C2H4O + H2O → HO–CH2CH2–OH

Polyethylene glycol: HOCH2CH2OH + n(CH2CH2O) → HO(CH2CH2O)n+1H

Even though it is the same basic molecule as ethylene glycol repeated many times, PEG molecules have very different properties, depending on how many are linked together. The number 3350 refers to the weight of the molecule, which is an indication of its size, in this case it’s a large molecule. PEG can be as small as 400 and as large as 15,000, but 3350 is a large molecule. The larger a molecule, the less likely it is to be absorbed by the body.

The weight of the molecule is very important.  PEG 3350 behaves differently than PEG 400 does, and differently than Ethylene glycol does. What is applicable to one molecule may not apply to another. PEG 3350 is a very stable molecule, which means that it doesn’t change its state (or break down) easily.

Is it possible through some mechanism, that Polyethylene glycol is responsible for the development of the neuropsychological issues in children?
I would be very shocked if the symptoms were caused by PEG 3350. Because of PEG 3350s size, our body isn’t able to absorb it. Given these properties, it is highly unlikely that it causes these neurological symptoms.  I did a review of the literature before we spoke and there’s nothing that supports PEG 3350 with lasting side effects or that explains how it could potentially cause it. Most reported side effects are linked to its laxative properties: abdominal discomfort, cramps, bloating, diarrhea.

The hypothesis put forward by some is that if improperly stored PEG 3350 breaks down into ethylene glycol and that this degradation combined with prolonged exposure in chronically constipated children causes the symptoms being reported. I am skeptical of this hypothesis due to the stability of PEG 3350. As I mentioned before PEG 3350 is very stable, so it would take a lot for it to break down due to improper storage.

I do understand that in 2008 trace amounts of ethylene glycol (15 µg/ml) were found in eight bottles of Miralax. This is a very small amount and is essentially harmless to an adult. But the question is, is that amount enough to cause problems in a child, especially if the child is exposed daily and over a long period of time (for example years). This is not something that I know the answer to as ethylene glycol toxicity is usually seen in the hospital, so I asked Matthew Hartings, a professor of chemistry at American University in Washington, DC.

Matthew confirmed what I thought, which is that the dose found in the bottles is not enough to be toxic to a child in a single dose. Matthew calculates that for a child to consume a toxic dose of ethylene glycol at the doses found in the bottles, they would need to consume 1L of the powdered product. The product isn’t available for retail consumer purchase in packages that large. He also says that ethylene glycol does not bioaccumulate so it’s unlikely that prolonged exposure to ethylene glycol could cause problems through that mechanism.

Matthew and I both agree that the ethylene glycol should not be in the bottles period and it’s not a good thing and it’s unacceptable that the manufacturer couldn’t account for how it got there.  It’s never a good thing when something that shouldn’t be in a product winds up in it, even if the dose isn’t enough to cause harm.

So what exactly does PEG 3350 do, and why is it in laxatives?
It’s an osmotic laxative, which means that it attracts water. Our intestines are very good at absorbing water, which is part of their jobs, but when a child (or an adult) becomes constipated their stools become very hard with very little water in them, and it makes them difficult and sometimes painful to pass. PEG 3350 holds water in the intestines which allows the stool to soften, which makes it easier to pass normally. It is a passive laxative, which means that it doesn’t cause the intestines to contract or actively push stool through. This is why it has been used so much for children. It is important to note that the main reason why it can express an osmotic force to retain water in the intestines is because it isn’t absorbed by the body. It goes right through, from one end to the other.

Part of the concern seems to be that a medication that is only indicated for adults has been used for children, why has it been recommended off-label for use in children?
We knew that it is safe as a one-time use to empty a child’s bowels before a procedure. As we know it is safe in a large dose at one time, some doctors and pharmacists started to extrapolate that knowledge and say, maybe it is safe in a small dose over a longer period of time.

At the beginning of my career I didn’t see PEG 3350 used very much in children in part because the product was new to the market. At first I started seeing individual clinics using it and then [a large area pediatric hospital] started using it, shortly after it became much more common.

This isn’t to say that PEG 3350 hasn’t been studied in children. It has been studied extensively and has shown to be safe and more effective than a placebo. But it hasn’t gone through the same level of trials that we require before approving a drug for adults. I know in the United States the Food and Drug Administration (FDA) is funding a study of the long-term safety of the use of PEG 3350 in children with chronic constipation, at the Children’s Hospital of Philadelphia (CHOP), but I don’t know what prompted the study. I see it as a good thing that can help confirm safety in a longer-term use. The more studies we have, the more confident we can be in a product’s safety.

I think a lot of parents are wondering why doctors are recommending a medication for children that isn’t approved for children.
As you know, it’s very difficult to get approval to test drugs on children. It’s pretty obvious why. Would you allow someone to test a drug on your child? You don’t know what the drug will do to your child. No one would sign their child up for that. It’s not ethical, so we don’t test drugs on children in large trials. Unfortunately what this means is that we sort of test things in the real world. We take that little bit of information that we have in one area and we extrapolate it and then we report on what we find, until we have enough data to have something similar to a clinical trial, then there’s usually a reclassification.

Additionally, and this is unfortunate to say, there isn’t a lot of money in pediatric drugs for large pharmaceutical companies. Kids are only kids for a little while, so it doesn’t offer good return on investment for them. Another deterrent for companies to invest and develop drugs for kids is that they don’t like to be sued, so they will usually go for the safest patients to treat: Adults with functioning kidneys and liver. Kids, the elderly, pregnant women, people with kidney or liver disease, these are all populations that are less researched, so treatment is trickier.

As companies hate to get sued, they will put on their labels only what they studied and they know is safe. That is common sense. But when a label says “Use for no more than 7 days without a doctor’s advice”, it doesn’t mean the product is poison if used for 8 days. It means if you need to use it for longer, you might have a more serious issue and should be examined by a doctor. Once you’ve been examined and it has been confirmed that everything is in order, under the doctor’s advice, you can use the product for longer, as long as there is a proper follow-up.

What are some things that parents can do to manage constipation at home if they don’t want to use an over the counter laxative like Miralax?
The most important thing is that parents talk to their doctor or pharmacist first if they have concerns about chronic constipation in their children. They best know your child’s medical history and are most familiar with the various treatment options.

With that said, there are some first line defense options that parents can try at home if they have a concern about acute constipation. These are things like prune or pear juice, or simply adding more of these fruits into their child’s diet, which I know can be difficult if their child is a picky eater. They can also ensure their child gets plenty of water and plenty of exercise, as those both really help with constipation.

Categories: Science 101 + Mythbusting