By Steve Hodges, M.D.
On a forum for childhood constipation, a mom recently posted:
My daughter has been struggling with constipation for 6 years now, and I have been to a lot of doctors. Now I have an appt. with a new GI doctor, and I want to eliminate each and every thing that may cause constipation. What kind of blood work and exams should I ask for to find out the reason for her constipation?
I hear this a lot! I specialize in treating children with enuresis (bedwetting and daytime wetting) and encopresis (poop accidents), and virtually all of my patients prove, via x-ray, to be severely constipated. These kids are so stuffed with stool that their rectums have stretched to more than twice the normal diameter.
When I show parents their child’s x-ray, they inevitably ask: “How did my kid get so constipated? What caused this? What tests should we get?”
Parents assume there must be some medical explanation — something related to “gut health” or gluten or a virus or a colon motility disorder. Or, if the child pees constantly, parents suspect diabetes.
Here’s the deal: In virtually all cases — I’ll cover the exceptions shortly — the answer cannot be found in lab tests. The explanation is more basic: We live in the 21st century.
In modern society, tons of kids need help pooping, and asking why is like asking why so many kids need braces.
The modern diet and lifestyle, our concept of decency (you can’t just poop anywhere!), the modern toilet (which takes us out of the natural squat position), our approach to potty training (must meet that preschool deadline!) — when the modern human brain is confronted with all this, high rates of constipation are inevitable.
Basically, we’re too smart for our own good. It would not occur to a cat, or to our prehistoric ancestors, to delay pooping when the urge strikes.
But today’s humans, particularly human children, constantly postpone pooping.
The urge to poop is triggered when stool arrives in the rectum, signaling the brain, via nerves, that it's time to evacuate.
But if we’re not near a toilet when we get the signal — if we’re in a car, on an airplane, in preschool story circle — or if we're engrossed in playing house or playing a video game, we’re going to override the signal by tensing our pelvic floor muscles and anal sphincter. We have the capacity to delay pooping for hours, even days. Children, especially, are masters of delay.
This delay has consequences.
The longer stool dwells in the rectum, an organ that was not designed as a storage facility, the more water is absorbed and the drier the stool. With each delay, more stool piles up. Eventually, the hard, dry mass can become so large — the size of a softball, even! — that the rectum stretches, losing the tone required to fully empty. The child also loses the ability to sense when it's time to poop.
Zillions of adults today suffer from constipation, so it’s no surprise that children — especially young children, with a lesser grasp on the importance of pooping every single day — are constipated, too.
Some children are more prone to constipation than others, because of their genetics and personality.
One preschooler may feel perfectly comfortable marching over to the toilet in the middle of story circle, whereas another might find the idea unthinkable. Some kids are cool with pooping in public restrooms. Others feel self-conscious and will not do it.
Plenty of K-12 studentes rarely or never poop (or even pee) at school — because their teachers restrict restroom access, because they don’t want to miss class, because they’re afraid of being teased or bullied, or because the bathrooms are dirty.
Heeding the body’s urge to poop may pose an even greater challenge to children on the autism spectrum and those with sensory processing issues; they may not fully receive the signal to poop or have the inclination or capacity to act on this urge.
Our culture's processed diets and relatively sedentary lifestyles — sitting all day is not what humans were built for! — make stool harder, slower, and more painful to pass, compounding the problem.
If kids are eating Lunchables or chicken nuggets, as opposed to fruits, veggies, and whole grains, their risk of constipation will be higher. If they're inactive, that factors in, too.
But, really, the key is the delay.
Plenty of sedentary kids with lousy diets evade constipation because they poop in a timely fashion. And plenty of athletes who eat quinoa and broccoli end up in my clinic because they’re in the habit of overriding the urge to poop.
None of this is a mystery that warrants lab tests.
What is warranted: aggressive treatment.
By the time a child is chronically constipated, the situation cannot be fixed with dietary measures. No amount of fiber will clear out the hardened mass clogging the rectum.
Basically, many kids today need their poop kept artificially soft, with osmotic laxatives, until they gain the maturity and judgment to poop when they feel the urge. Osmotic laxatives include PEG 3350 (Miralax), lactulose, magnesium hydroxide (milk of magnesia), and magnesium citrate.
But for chronically constipated children, laxatives aren't enough!
While physicians tend to push Miralax and more Miralax, the reality is, these kids need rectally administered treatments to stimulate bowel movements and clear out the hard, crusty stuff, so the rectum has a chance to shrink back to size and regain tone and sensation.
For constipated babies and toddlers, this means a glycerin suppository on any day that the child either 1.) doesn'’t poop at all or 2.) doesn’t fully evacuate. (Details are spelled out in The Pre-M.O.P. Plan.)
For toilet-trained children with enuresis and/or encopresis, daily enemas are needed, as explained in The M.O.P. Book: Anthology Edition.)
In nearly all children, treatments such as Pre-M.O.P. or M.O.P. will solve the problem.
But . . . there are exceptions.
Medical Conditions that Cause Constipation and Enuresis
Not long ago, I saw a 4-year-old patient who was having frequent pee accidents, a telltale sign of constipation. (The stretched rectum presses against the bladder, randomly triggering forceful hiccups.)
I x-rayed this child, as I do for all my enuresis patients, and expected the film to show a stretched rectum encroaching upon the child’s bladder.
But this child wasn’t constipated! His rectal diameter was normal, well under 3 cm, and the rectum harbored no stool.
An ultrasound revealed the culprit: posterior urethral valves. This a condition in which extra membranes develop in utero and block the flow of urine through the urethra, causing accidents and eventually, if not repaired surgically, bladder and kidney damage.
This disorder occurs in 1 out of 8,000 births, always in boys. It’s almost always picked up on prenatal ultrasounds, but some cases slip by. I’ve seen the condition twice in my career.
Cases like these are why I say “virtually” all cases of constipation — instead of “all cases” — have no underlying medical cause.
Below I list congenital conditions that can cause constipation in children. This is not an exhaustive list. It highlights the more “common” of these uncommon conditions.
In addition to the conditions listed here, diseases such as cystic fibrosis and hypothyroidism can cause constipation and incontinence. So can celiac disease, an autoimmune inflammatory disease of the small intestine spurred by eating gluten. In cases like celiac, where the root cause of constipation is a dietary intolerance, dietary changes don’t usually fix the problem but are important for preventing a recurrence.
When children with celiac (or an actual dairy allergy) develop encopresis and/or enuresis, they still need M.O.P. But when the cause of a child’s accidents is a neurological or anatomical condition, the fix is usually surgical.
As for diabetes, I’ve examined thousands of kids with urinary frequency (incessant peeing) whose parents feared diabetes, and exactly one tested positive for diabetes. In every other case, the child's stool-stuffed rectum was aggravating the bladder nerves.
Hirschsprung’s Disease
Children with Hirschsprung’s disease are missing nerve cells from part of the colon and the rectum. So, instead of getting pumped along through the bowel, stool gets stuck.
When a newborn doesn’t poop within 48 hours of delivery, that’s a red flag for Hirschsprung’s disease. Babies with Hirschsprung’s typically have additional symptoms, such as a swollen belly, pencil-thin stools, failure to thrive, explosive and bloody diarrhea, and vomiting.
Though Hirschsprung’s is usually diagnosed at birth, children with milder versions of the disease sometimes go undiagnosed until age 3 or later.
Hirschsprung’s disease is resolved by surgically removing part of the colon. I’ve never had a case in my clinic, though I encountered a child with this condition when I visited the clinic of a colleague.
Congenital Anorectal Malformation
In about 1 in 5,000 children, the anus or rectum doesn’t develop properly, and these kids have serious pooping problems that must be corrected surgically. Anorectal malformations are almost always diagnosed at birth and quickly corrected, although even with surgery these children may have difficulties pooping and need enema treatment.
Anorectal malformations include imperforate anus, where the opening to the anus is missing or blocked; anal stenosis, a narrowing of the anal canal; and an anteriorly displaced anus, where the anus isn’t located in its normal position.
I’ve never seen a patient whose anorectal malformations were not already diagnosed and corrected surgically. When the rare case is referred to me, it’s because the child has resulting bladder issues.
Spinal Cord Abnormalities
Children with nerve problems in their lower spine have abnormal bowel function, known as “neurogenic bowel,” because of faulty communication between their brain and their bladder and bowels. As a result, their bowels move at a pokey pace. In addition, these children can’t sense the rectum is full and/or can’t fully empty the rectum.
Conditions that cause neurogenic bowel include spina bifida, which occurs when the spine and spinal cord don’t form properly, and a related condition called tethered cord syndrome.
Spina bifida is almost always diagnosed before or just after birth. With these kids, part of the spinal cord is exposed through a gap in the backbone.
With tethered cord syndrome, the spinal cord, which normally floats freely inside the spinal canal, is stuck to the spinal canal and can become stretched and damaged. Telltale signs include a dimple or tuft of hair on the lower back and a lower spine that veers off to the side. These kids also tend to have poor reflexes or weakness in the legs.
I’ve seen plenty of patients with spina bifida for a variety of incontinence issues, but all were diagnosed long before visiting my clinic.
However, I’ve had two patients with tethered cord syndrome, a 4-year-old and a 13-year-old, who had not been diagnosed before their office visits. In both cases, their symptoms — encopresis, daytime enuresis, and bedwetting — suggested garden-variety causes of constipation.
It was only upon examination and further questioning that I discovered these kids were outliers.
The 4-year-old had the telltale lower-back dimple and the off-kilter lower spine, and
when I asked about leg weakness, his mom said, “Oh, yeah, his left foot sometimes goes numb.”
The 13-year-old had no dimple and a spine that was barely deviated. I only thought to ask about foot weakness — which he did report — because his accidents came completely out of the blue during a growth spurt in puberty. Surgery to untether his spinal cord fixed the problem. The 4-year-old is headed for the same surgery.
You’ve probably heard the aphorism, common in medicine, “When you hear hoof beats, look for horses, not zebras.”
While these cases are reminders that sometimes hoof beats do come from zebras, in 99% of cases, it’s horses you should be looking for.