By Steve Hodges, M.D.
Are children at increased risk for bedwetting if they feel emotionally stressed, if they drink caffeinated beverages, or if they did not receive toileting instruction?
Certainly not.
Yet a new study published in Frontiers of Pediatrics purports to find that “exposure to stressful events,” such a divorce, along with caffeine intake and lack of toilet training, are a “predictors” of nocturnal enuresis (bedwetting).
Now, if I blogged about every misleading study published on nocturnal enuresis, I’d have no time to practice medicine. Plus, I’d bring attention to studies that just don’t warrant publicity.
Still, taking a close look at a flawed study such as this one demonstrates how bedwetting myths have such staying power.
Essentially, researchers take an age-old theory that sounds plausible — for example, that bedwetting may be caused by emotional stress or caffeine intake — and then conduct a study that purports to confirm this theory but actually doesn’t. Lots of fancy math, graphs, and footnotes create the illusion of evidence but, in fact, distort reality.
What we have is a vicious cycle: Fictions about bedwetting beget lousy studies, which keep these fictions circulating, which spawn more lousy studies.
I’m mentioning the Frontiers in Pediatrics study, conducted in Ethiopia and delivered to me via Google Alerts, to debunk some damaging myths about bedwetting and to help folks become more discerning about media headlines.
In the Ethiopian study, researchers administered questionnaires to parents of 730 children ages 5 to 14. Based on parent reports, 22% of the children experienced bedwetting, on the higher side, but not out of line with the rate of enuresis found elsewhere.
Let’s start with what the Ethiopian study gets right: Bedwetting can be devastating for children.
As the authors note, nocturnal enuresis can lead to “feelings of guilt and shame,” crushing a child’s self-esteem. Children with enuresis “may be reluctant to participate in overnight activities, such as sleepovers or camps, fearing embarrassment or ridicule from their peers. This can result in social withdrawal or limited social interactions, anxiety, and depression.”
All true. I hear this every day from my patients and their parents. The emotional fallout from enuresis is what prompted me to write Bedwetting and Accidents Aren’t Your Fault and other children’s books about enuresis.
So, I understand the Ethiopian researchers’ motivation to investigate causes and/or predictors of nocturnal enuresis. As the authors note, this information would allow science to “develop targeted strategies and interventions.”
Except that . . . the cause of nocturnal enuresis has been known for decades, and proven interventions already exist!
Research has long established that the root cause of nocturnal enuresis is chronic constipation — that is, a rectum enlarged by the pile-up of stool.
X-ray any child with enuresis, as I routinely do in my clinic, and you will see a clogged rectum stretched to two or three times its normal diameter. The enlarged rectum aggravates the nearby bladder nerves, causing the bladder to spasm forcefully and empty randomly, day or night, even before it has been filled with urine. The child receives no advance notice and can’t possibly get to the toilet on time.
It does not matter one iota whether the owner of this bladder has imbibed caffeine before bed or has “experienced exposure to stressful events,” such as parental divorce, death of a loved one, or moving to a new home.
If you clean out the clogged rectum and keep it empty for months, the rectum will shrink back to size and stop aggravating the bladder. That’s when accidents stop.
Yet the Ethiopian researchers found no connection between constipation and bedwetting. How can that be?
Their questionnaire actually did ask parents whether their child showed signs of constipation, such as “infrequent painful defecation” and poop accidents. But almost none of the parents reported such signs, so the researchers had no data to analyze and therefore dismissed any possible connection between constipation and enuresis.
But this hardly means these kids were free of constipation!
Even physicians frequently overlook constipation in children. The signs are often subtle, and the usual diagnostic techniques — feeling a child’s abdomen and asking about a child’s pooping history — are entirely inadequate.
Many parents have no idea how often their children poop, whether their child’s stool is hard or soft, whether pooping hurts their child, and so on. (I experienced painful pooping throughout my childhood and certainly never reported this to my mom!) Even children who poop every single day can nonetheless harbor a large stool mass in the rectum. You can only rule out enuresis with an x-ray (or a procedure called anorectal manometry). Even then, you have to know what you’re looking for. Many radiologists report a “normal stool burden” because they are looking at stool in the entire colon rather than in the rectum, the only place that matters.
So, the idea that a sample of Ethiopian parents, about one-fifth of whom lack literacy, could accurately diagnose constipation in their children is highly unrealistic.
Also, on the subject of constipation, the authors cherry-pick data from other studies. The Ethiopian study found that girls have a higher rate of bedwetting than boys and note that a study out of Thailand produced a similar finding. But what the Ethiopian authors ignore: the Thai study found a significant association between bedwetting and poop accidents (encopresis)! The sole cause of encopresis is chronic constipation.
As for the purported stress-bedwetting connection, the Ethiopian questionnaire did turn up 171 children, 23% of the sample, who had been “exposed to stressful experiences,” the most common of which was parental divorce. The researchers performed some math wizardry and concluded that children exposed to stressful events had “20 times the risk” of developing nocturnal enuresis compared to children not exposed to stress.
Twenty times! That’s roughly a smoker’s increased risk of developing lung cancer compared to a nonsmoker’s. (Smokers are 15 to 30 times more likely to develop lung cancer than nonsmokers.)
It is indisputable that smoking causes lung cancer, but no legitimate evidence shows that emotional stress causes, or even influences, nocturnal enuresis and no reason to even think it would. This is a classic case of “correlation is not causation.”
The Ethiopian authors themselves note that enuresis “may cause panic attacks, mood disorders, and depression” and these kids feel “shame and isolation.” Could it be that the children in this study experienced stress because of their wetting accidents and not the other way around?
I can tell you that when my patients’ bedwetting resolves, so does their stress and anxiety.
Or maybe the Ethiopian children felt stress because of how their parents reacted to their wetting accidents. As the authors note, enuresis can cause “emotional stress within the family” and “parents may feel frustrated.” Worldwide, children are shamed, blamed, and even physically abused (in some cases, murdered) by parents who are exasperated or angry about the bedwetting.
The authors suggest their findings confirm what is already known. “In the community, as well as by clinicians, bed-wetting is frequently viewed as a psychological problem,” they write. That perception certainly exists. But it happens to be wrong. The fact that many people believe something doesn’t make it true.
The same applies to their caffeine findings. The authors found that children who never drink caffeinated beverages had an 84% lower risk enuresis compared to those who do drink these beverages.
That finding sounds dramatic! But again, the supposed link doesn’t hold up.
By way of explanation, the Ethiopian authors state that “caffeine-containing drinks cause irritation the bladder, so urination may occur” and that caffeine is a “mild diuretic, which results in the kidneys releasing more water from the bloodstream, as a result the bladder becomes filled and urination can occur.”
But “urination can occur” is not the same thing as “the child might have an accident.” A child with normal bladder function would simply sense the urge to pee and use a toilet, not have an accident.
Oddly, the only study the authors cite in support of their caffeine theory, an American study in the Journal of Pediatrics, concluded that “caffeine consumption and enuresis were not significantly correlated” (italics are mine). So, again, the Ethiopian authors have mischaracterized the research they cite.
Children with enuresis have accidents because their bladder spasms and empties even before the bladder is full. So, it doesn’t really matter if caffeine makes the bladder more full. These kids will have accidents either way.
I’ve heard the caffeine theory a million times. Most parents in my clinic have heard about it, too, and have tried limiting their child’s caffeine intake. If cutting out caffeine were actually a solution to bedwetting, no child with enuresis would need to see a urologist.
Finally, let’s consider the third supposed “predictor” of enuresis: lack of toilet training. In this study, children who had no instruction on when and how to use a toilet “appropriately” were found to have seven times risk of developing nocturnal enuresis than those who were taught proper toileting practices.
But this question overlooks a scenario I see all the time: When children are chronically constipated, it is difficult, if not impossible, to toilet train them. Their signals to pee and poop are on the fritz, so they just cannot control when their bladder and/or bowels empty, no matter how hard they try.
It’s possible that the children who did not receive toileting “instruction” actually did receive training but couldn’t follow through because they were constipated. It’s unclear from the study whether any of the children also had daytime enuresis, but in general, about one-third of children with bedwetting also have daytime wetting. In some cases, daytime accidents resolve with age, even without treatment, while nighttime wetting persists. Perhaps some of the subjects classified as “never have been toilet trained” were kids who were unable to follow instructions at first and eventually could do so but still wet at night.
I can tell you that all my bedwetting patients were toilet trained by their parents, with great care and diligence. Lack of training does not cause bedwetting. (However, toilet training a child too early can dramatically increase the child's risk for developing chronic constipation, enuresis, and/or encopresis.)
By the way, the Thai study I mentioned above, cited by the Ethiopian authors, found “no association between bedwetting and toilet training.” But that finding was disregarded.
Enuresis is highly treatable, even in teenagers, but often requires aggressive treatment such as the Modified O’Regan Protocol (M.O.P.). Treatment can be implemented very inexpensively, with nothing more than a syringe and liquid glycerin, as I explain in the M.O.P. Anthology.
Unfortunately, many studies, by dismissing constipation and focusing on irrelevant variables, make it even less likely that children with enuresis will get the treatment they need.
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