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Constipation in Children, Enemas, and the Gut Microbiome

By Steve Hodges, M.D.

Q: My mother, a retired physician, has expressed concern about my daughter’s gut microbiome and malabsorption while on Multi-M.O.P. with two liquid glycerin suppositories (LGS) a day. What would you say in response to this concern?


A: The small intestine is involved in the digestion of food and absorption of nutrients, whereas the intestine is mostly involved in absorbing water. Since enemas clear stool from the rectum, the end of the colon, nutrient absorption is minimally affected.


As for the gut microbiome, if a child is backed up enough to have pee and/or poop accidents, they’ve already altered their gut microbiome. There’s plenty of data showing that impacted stool negatively affects the microbiome — for example, by reducing diversity and altering metabolism of gut bacteria and possibly contributing to low-grade inflammation in the gut.

From my perspective, cleaning out the rectum with liquid glycerin is far more beneficial for the child’s health than allowing rectal stool to sit idle. And it’s certainly more effective than attempting to clean out the rectum with PEG 3350 or other oral laxatives.


Also keep in mind that in the scheme of things, M.O.P. is a short process. Most children with enuresis and/or encopresis have been chronically constipated for years and would continue to be clogged without the regimen. A few months on any M.O.P. variation is a blip in time and will restore the rectum to good health.


Q: I’m treating my eldest son, age 7, for encopresis with Multi-M.O.P. However, I have two other boys, ages 4 ½ and 6, who wet at night only and have no obvious signs of constipation. I’m stripping three beds most mornings. I was going to start with bedwetting alarms for my younger two. With no obvious signs of constipation, I feel M.O.P. is excessive. Should I request x-rays to see if there is any blockage, pressing on the bladder?


A: Bedwetting actually is a sign of constipation, but this important sign is commonly overlooked. Parents and doctors alike tend to focus on the more well-known red flags, like infrequent pooping or straining to poop. As a result, countless cases of enuresis go untreated, and bedwetting persists for years.



In reality, a child can poop every single day, never strain, and consistently produce soft stool and nonetheless have a clogged, enlarged rectum. You can see it on an x-ray. Soft, newer stool just oozes around the hard mass that is stretching the rectum and triggering unwanted bladder contractions. But all this is invisible, so adults chalk up the child’s accidents to “deep sleep,” an “underdeveloped bladder," stress, or any number of fictional “causes” of enuresis.  


An accurate definition of constipation is “incomplete evacuation,” not “infrequent pooping.” Any stool that is left behind each day contributes to the accumulation, no matter how often the child poops.

With enuresis, my motto is "Constipated until proven otherwise." It's a rare case of enuresis that does not stem from an enlarged rectum. The unusual medical conditions that cause bedwetting in the absence of constipation are discussed in the M.O.P. Anthology 5th Edition (see page 40). It’s unlikely your two younger children have these conditions, especially given that your older child has encopresis. A tendency toward chronic constipation runs in families, and some children have bladders that are extra sensitive to an enlarged rectum.

I'd start with an x-ray for your younger children and hold off on the bedwetting alarms. Using an alarm with both children will require you to wake up twice a night and interrupt your children's sleep, too, and alarms don’t address the root cause of enuresis. Alarms can be useful as a gauge of how well a bowel-clearing treatment is working (see page 112 of the Anthology). However, in my experience, constipation treatment is a better use of a family’s energy than a bedwetting alarm.


Q: Can a teen with persistent enuresis expect to ever get dry overnight? My 15 y.o. has been doing Multi-M.O.P. for over 5 months, and his most recent x-ray showed good progress, but the accidents have continued. Demospressin works well for my son, but he wants to save it for when he really needs it, like sleep-away situations. We thought he’d be dry on his own by now. Do you have statistics about how often this happens? My son doesn’t want to stay on meds the rest of his life.


A: There’s no reason to think your son would need stay on medication indefinitely. Sometimes, improvement in enuresis will lag several months behind an improved x-ray. Though the rectum is empty, it remains stretched out, sometimes to as much as 7 or 8 cm (under 3 cm is normal). If the child’s bladder is highly sensitive to a dilated rectum, accidents will persist until the rectum shrinks to the point where it no longer aggravates the child’s bladder. I wish I could predict when this will happen in a given child, but I can’t.


From experience, I do know that in a teen, whose rectum has likely been dilated for many years, rectal healing usually takes a lot longer than it does in a younger child.


The fact that your son responds to desmopressin is a great sign, suggesting dryness is on the horizon. The medication, which suppresses urine production (see page 114 of the Anthology), rarely works in a child with a clogged rectum. In situations like your son’s, I recommend my teen patients take medication rather suffer through accidents. They continue with M.O.P. (that’s important, to make sure the rectum doesn’t refill) and periodically stop the medication to assess whether they can stay dry without it.


The back-up plan, if all three categories of enuresis medication (described on pages 114-115) do not halt the accidents, is a bladder Botox injection. In a child with a clear x-ray and good compliance with M.O.P., Botox is almost certain to stop bedwetting. By the time Botox wears off, several months down the road, the child’s rectum will likely be healed, and the accidents won’t come back.


The only statistics on teenagers with enuresis show that without treatment, bedwetting often persists into adulthood. I don’t keep statistics on my teen patients specifically. I just know that with the progression of M.O.P., medication, and Botox, they all stop wetting. But the process often takes longer than families expect.


Q: My 5 y.o. daughter, who has both daytime and nighttime enuresis, takes 5 mg Vesicare per day alongside Multi-M.O.P. (Her encopresis has resolved.) The Vesicare has never gotten her dry. Is it worth exploring bumping up her dose to 10 mg? Or should we wait out improving the constipation, and therefore enuresis, just through enema therapy?


A: If medication doesn’t work, I don’t recommend taking it. Vesicare is one of the anticholinergics, medications designed to calm bladder overactivity, and, like other enuresis medications, usually doesn’t work unless the child’s constipation has largely been resolved. The effect is usually immediate; you’ll know within a week or two whether it’s helping.


If your daughter’s current dose of Vesicare doesn’t produce side-effects, such as dry mouth, facial flushing, or worsening constipation, there’s no harm in trying a higher dose, but I suspect she’s just not there yet. Children who begin with both encopresis and enuresis tend to be the most stopped up, and there’s only so much you can do to accelerate rectal emptying and healing.


If you persist with Multi-M.O.P., the accidents will likely disappear, and she won’t need medication at all.


Q: My twin boys, age 7, have been on Standard M.O.P. for 10 weeks. Both are consistently dry at school now (previously almost unheard of prior to M.O.P.) and have had some completely dry days. Each boy has also had 5 or 6 dry nights since we started and both poop on their own almost every day. Based on this progress, would you suggest continuing with M.O.P. or should we move to Multi-M.O.P.?


A: I’d stay the course. You can't expect nighttime dryness to improve until daytime dryness stops, so it’s unlikely the boys could progress any faster. My rule of thumb is to change the regimen after any 30-day period without progress, burt your children are making terrific progress. If they're already pooping on their own in addition to the enema, they're "ahead" of kids who need Multi-M.O.P. I don't see a reason to step it up.


Q: Both my children have had periods of dryness at night while they were still wetting during the day. Is that out of the ordinary? Our doctor told us their accidents were behavioral.


A: Though most children with daytime wetting also wet overnight, there are a surprising number of children who experience daytime wetting only, and their accidents are often mistakenly perceived as behavioral. Parents and even many doctors assume that if a child can sleep 10 hours without peeing, the child should be able to stay dry during the day and therefore must be “acting out” or ignoring signals to pee.


But that’s not the case. If you x-ray these kids, you’ll see the same clogged, stretched rectum typical of children with bedwetting only. Overactive bladders don’t follow rules! My guess is that kids with daytime but not nighttime wetting sleep in a position that renders their bladder nerves less aggravated at night. Regardless of whether the child wets overnight or during the day or both, treatment is the same.





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