What Parents Need to Know About Constipation

by Howard J. Bennett, MD and Benny Kerzner, MD

Constipation is a frustrating problem for parents and children alike. In addition to causing recurrent stomachaches and poor appetite, it increases the risk for urinary tract infections and bedwetting. The pain associated with constipation varies from mild to severe. It’s usually located around or below the belly button and often improves after a child poops.

Many factors govern the time is takes for food to pass through the digestive system including what a person eats and drinks as well as their genetic makeup. The longer it takes for waste to move through the intestine the more likely someone is to become constipated.

Constipation is rarely due to a serious underlying illness in children. It accounts for 5% of visits to primary care doctors and 25% of first-time visits to pediatric gastroenterologists. However, the diagnosis may be elusive because patients often present with symptoms seemingly unrelated to pooping.

Review of Digestion

Food moves from the mouth to the stomach via the esophagus. Although swallowing is voluntary, once food enters the esophagus it’s propelled forward by involuntary, wavelike contractions of muscles along the gastrointestinal tract.

Approximately 2 quarts of water are secreted into the intestine every day delivering chemicals needed to digest what’s been eaten. The primary function of the large intestine (colon) is to reabsorb water that remains at the end of the digestive process. If someone is constipated, the problem can get worse because water will continue to be reabsorbed the longer stool remains in the colon.

The Mechanics of Defecation

Because digestion isn’t under conscious control, most people don’t think about it until it’s time to poop. When waste moves into the rectum, the last 6 inches of the colon, stretch receptors signal what’s happening.

The internal and external anal sphincters are donut-shaped muscles that surround the anus. The internal sphincter, which is not under voluntary control, is contracted until stool enters the rectum triggering the muscle to relax. At that point, you can either retain or release the contents by squeezing or relaxing the external sphincter, which is under voluntary control. (Children don’t have control of the external anal sphincter until 18 months or later, which explains the timing for toilet training.)

The pelvic floor is a group of muscles that support the bladder, intestine and reproductive organs. One of the muscles is a sling that pulls the lower end of the rectum forward creating a “bend” to help retain stool in the colon. The angle of the bend is the greatest when standing and the least when squatting. The use of toilet stools is based on this anatomic alignment, i.e., the rectum straightens when squatting thereby creating a more direct path for stool to exit the body.

Normal Stooling Patterns

The frequency and consistency of bowel movements varies between children. Breastfed babies typically have 4 to 8 loose to runny stools per day, and formula fed babies have 2 to 4 pasty stools per day. Breastfed babies often have a reduction in stooling around the second month and may go as little as 1 to 2 times per week even though the consistency of the poops remains the same. It’s unclear why this slowdown happens, but it resolves in a month or two. Between 12 months and 3 years, children have 1 to 2 soft stools per day, and from 4 years on they usually go once a day to every other day.

The Case of Constipation That Isn’t

Babies less than six months sometimes go through a stage that parents may incorrectly interpret as constipation. These babies strain and sometimes cry for 10 minutes or more while trying to poop. When the baby finally goes, the poop is surprisingly soft. In an effort to treat the problem, parents may resort to gripe water, rectal suppositories or other rectal devices designed to help the baby pass gas. From a medical perspective, as long as an infant is feeding well and doesn’t have features of illness such as a swollen or tender belly, this is most likely a temporary phase called infant dyschezia (dis-kee-juh). It’s thought to occur because the pelvic floor muscles don’t relax in response to poop entering the rectum. The problem doesn’t need to be treated and resolves as the baby matures. However, you might be able to reduce an infant’s discomfort by placing the baby on his back, flexing his hips and knees or holding a warm, wet washcloth against his rectal area for a few minutes.

Common Constipation Triggers

• Introduction of new foods: Babies become constipated at two predictable times: six months when they start spoon feeding and 12 months when they start drinking whole milk. 
• A low-fiber diet: Many children not only shun fruits and vegetables, but also prefer milk products, fatty foods and refined carbohydrates (sugar, white breads, crackers, rice, pasta) all of which can cause constipation. 
• Toilet training: Preexisting constipation can make toilet training more difficult. Also, toilet training itself is a risk factor for constipation, especially in a child who isn’t ready to learn this skill.
• Daycare and School: If parents feel pressure to toilet train their child because it’s required for daycare or preschool, constipation may result because the child picks up on the stress and resists pooping. If possible, find a center with a more relaxed toilet training policy. Many school-aged children, especially girls, hold in their urine and stool because they think the bathrooms are gross. A doctor’s note letting the child use the nurse’s bathroom may lessen the anxiety.
• Family Stress: The birth of a newborn, school problems and related issues can lead to constipation.
• Illness: Children may develop constipation because they eat less and/or become dehydrated when they’re sick. 
• Lack of exercise: Sedentary behavior or being bedridden because of an illness or injury can cause constipation for mechanical reasons, i.e., activity helps move poop through the body.
• Waiting too long to poop: Many children have a tendency to wait until the last minute to pee or poop. The former can lead to daytime wetting accidents and promote UTIs. The latter can cause constipation. Unfortunately, this behavior is easier to observe than correct as children often resist paying attention to their bodily cues. Gentle reminders can help.

Myths About Constipation

There are a number of beliefs about constipation that are not supported by research. 

• Drinking more water does not treat constipation. Although a dehydrated child may become constipated, giving additional water to a well-hydrated child has no impact on pooping. The extra water just increases urination because it’s absorbed from the intestine. 
• Prebiotics and probiotics do not prevent or treat constipation. 
• A low-fiber diet may cause constipation, but once present, additional fiber won’t reverse it. Prunes, prune juice, apple juice, etc. help because they contain a chemical that acts as a laxative not because of their fiber content.

The Constipation Cycle

Some children react more intensely than others when faced with mishaps or day-to-day frustrations. For instance, if a child chokes while eating, it can lead to a fear of eating in the future. Similarly, having a painful stool can make a child anxious about pooping. In the child’s mind, holding back the next poop is the logical way to prevent the pain. Unfortunately, this short-term solution results in an ongoing cycle of pain and stool withholding.

Figuring out if a child is withholding or trying to poop can be tricky. Parents may think a child is struggling to go when he’s actually desperately trying to hold it in. A child who’s withholding a poop usually stands, tightens his abdominal and buttocks muscles and may cross or press his legs together. Younger children often cry during the process.

Diagnosing Constipation

A child is considered to be constipated if he experiences at least 2 of the following over a 4-week period: (1) Two or fewer poops per week; (2) A history of excessive stool retention; (3) A history of hard or painful stools; (4) A history of large diameter poops or ones that block the toilet.

The first step in making a diagnosis is knowing what the child’s stool looks like. Kids are unable to reliably describe the consistency of their stools. Further, once a child is toileting independently, parents usually don’t know what’s going on. 

To get accurate information, we ask parents to become poop detectives for a week or two. The Bristol Stool Chart helps describe what’s been observed. Types 1 to 3 are difficult to pass (constipation). Types 4 and 5 are easy to pass (normal). Type 6 is difficult to control and Type 7 is diarrhea.

Complications of Constipation

Children can develop small cuts called anal fissures if a large or hard stool overstretches the anus. When this happens, bright red blood will be seen on toilet paper or in the toilet bowl. Fissures usually heal soon after the constipation has been corrected. 

The rectum is behind the bladder. Pressure from an overly full rectum can compress the bladder causing a sudden urge to pee. Children may wet themselves (day or night) because they haven’t learned how to respond to these sudden, intense signals. 

Video: The Poo in You. Credit: Children’s Hospital in Colorado. See link in article for larger version.

Treatment

We divide treatment into three loosely defined groups. 

Group 1 has occasional constipation with or without stomachaches, but the pain isn’t severe. They usually respond to dietary and behavior management, but may occasionally need medication. We suggest reducing or eliminating milk products as well as processed carbohydrates and eating more fruits and vegetables, especially prunes, pear, peaches, plums, apples or their juices. If a child turns up his nose at these foods, try adding them to smoothies.

If a child is out of diapers, have him sit on the toilet for 5 minutes after breakfast and dinner even if he doesn’t feel the need to go. This takes advantage of the reflex that starts intestinal contractions after a person eats. Distractions should be kept to a minimum, but he can bring a book or small toy if it improves cooperation. Keep a daily record of bowel movements and provide rewards (praise, stickers, etc.) if the child cooperates, even if he doesn’t poop.

Ideally, a child’s knees should be at hip level or above with his feet flat against the floor or on a stool. This position straightens the rectum and relaxes the pelvic floor muscles, which facilitates pooping. Older kids can do this when they sit on a toilet or potty. If your child is still in diapers, you can encourage him to flex his hips and knees when pooping.

Group 2 has frequent episodes of constipation with more intense or recurring pain. They require medication in addition to basic suggestions. Recommended doses of some commonly used laxatives are listed in the following table or you can speak with your doctor. 

There are two types of laxatives. Osmotic laxatives “hold” water in the colon yielding softer poops, which are easier to pass. Examples include polyethylene glycol 3350 (Miralax and others), magnesium hydroxide (milk of magnesia and others) and lactulose. The fruits listed for Group 1 contain sorbitol, which acts as an osmotic laxative.

Stimulant laxatives increase the strength of intestinal contractions helping to “squeeze” poop through the colon. Examples include senna (Ex-Lax and others), bisacodyl (Dulcolax). They’re not addictive, despite what you may read online.

Glycerin suppositories have properties of both osmotic and stimulant laxatives. Because they’re inserted into the rectum, they work faster than oral laxatives. However, they are not to be used on a daily basis. 

Miralax is our first choice for Group 2 because it works well and is readily taken by most children. However, in some cases, you’ll need to use a stimulant laxative as well to get the desired effect. We prefer senna over bisacodyl because of the taste. Regardless of the medication used, start with a low dose and adjust every three days until you get the desired effect. 

Group 3 has chronic constipation with stool retention and possibly encopresis. They require more intensive management with a doctor’s supervision. Treatment begins with a “bowel evacuation” that involves taking enough oral medication or enemas to completely empty the colon of retained stool. This is followed by long-term laxative use to prevent stool from reaccumulating in the colon.

Side Effects of Medication

Side effects of laxatives are usually mild and include bloating, nausea, gas pains, abdominal cramps and diarrhea. They occur because laxatives increase the force of intestinal contractions and/or the amount of water in the colon. Side effects are managed by adjusting the dose. 

A Few Words about Miralax

Pediatric gastroenterologists began studying the safety and efficacy of Miralax before it became available without a prescription in 2006. One study showed that taking it daily for 12 months was safe and effective in infants as young as six months. However, similar to many medications, Miralax has only been approved by the FDA for use in adults. This fact did not deter pediatric gastroenterologists from recommending Miralax, but pushback occurred online by parents fearing that contaminants were present. Studies failed to confirm this and in the past 18 years, additional published research has supported the safety of Miralax in children.

Dosages of Commonly Used Laxatives in Children

Notes

• Always start with the lowest dose listed and work up if needed.
• Some doses are listed according to weight (mg); others use volume (tsp or ml). To get the correct dose, you must use a measuring teaspoon, not the type you eat with. 
• 5 ml equals one measured tsp; 30 ml equals one fluid ounce.

Follow-up

There is a high relapse rate after treating constipation in both mild and severe cases for a number of reasons. 

• Children who are predisposed to constipation are more likely to get it again. 
• Parents may be reluctant to use enough medication to control the child’s symptoms and/or they don’t use it long enough. They may also forget to schedule follow-up appointments with the doctor because things have improved. Lastly, parents may worry the medication is dangerous or that their child will have to take it for years. Speak with your doctor about these concerns. 
• If a child has had constipation for a long time, the rectum may be stretched even if he never developed fecal impaction or encopresis. It can take 12 months or more for a distended rectum to regain its normal size and strength. If parents stop medication too soon, it’s easy for stool to reaccumulate and the constipation will recur.

Additional Tips for Children 18 Months to 3 Years

• If a child recently began toilet training, stop and go back to using diapers or Pull-ups. 
• Most children this age can’t understand that letting go of their poop will stop the stomachaches. Despite how tempting it is, don’t say something like this: “Sweetie, are you sure you don’t want to poo on the potty? It will make your tummy ache go away.” Although well-meaning, such comments will work against you. Make sure other family members avoid these remarks as well.
• Gradually increase the dose of medication until your child’s stool is too soft or runny to hold it back. Eventually, he will realize he can go without pain.
• Once the constipation is clearly resolved and the passage of stool is painless, encourage your child to squat on the floor while wearing a Pull-up to make it easier for the poop to come out. Three-year-olds may be ready to use the potty at this point.

Additional Tips for 3 to 5 Year Olds

• Explain that poop is the body’s “trash” that’s left over after eating, and the body needs to get rid of this trash to keep you healthy. 
• If your child won’t use the potty, let him go in a Pull-up because the most important thing is to break the withholding cycle.
• Your child can wear a Pull-up all the time or keep a stack of them in the bathroom. When he feels the urge to go, he can put on the Pull-up himself or ask you for help. He can then go in the Pull-up, flush the toilet and change back into his underpants.
• If the timing seems right, you can gradually restart toilet training. One trick is to cut a small hole in the bottom of the Pull-up before your child puts it on. He can then sit on the toilet when he goes. Overtime, you can make the hole bigger and bigger until the poop falls through the bottom. Your child will then realize he’s not really going in the Pull-up anymore, and you can (hopefully) transition to using the toilet.
• If you solve the constipation problem, but your child continues to resist toilet training, talk to your doctor or consider seeing a therapist to address any underlying issues surrounding the problem.

Measuring Success

When adequately treated, a constipated child should have Type 4 or 5 stools at least every two days. An ideal stool can be long, but should be soft and 1-inch in diameter or less. If you notice things moving in the wrong direction, you need to act before the situation get worse, especially if the child has a history of fecal impaction or encopresis.

Dr. Bennett is the author of The Fantastic Body and It Hurts When I Poop: A Story for Children Who are Scared to Use the Potty. Dr. Kerzner is the former Chief of Pediatric Gastroenterology at Children’s National Medical Center.