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Ex-Lax Safety in Children: Are “Toxicity” and “Tolerance” Legit Concerns?

By Steve Hodges, M.D.

It's a myth that Ex-Lax is unsafe for children with chronic constipation.

Parents often ask me how long children with chronic constipation can safely use stimulant laxatives such as senna (Ex-Lax).

 

Just the other day, a Canadian mom whose child struggles with nocturnal enuresis (bedwetting) emailed: “I am getting some pushback from my GI over the long-term use of senna. The doctor recommends a maximum of 4 days.” 

 

The GI’s advice struck me as wildly conservative (though I suppose “wildly conservative” is an oxymoron!). I told this mom I have patients who use senna daily for two months or more and then multiple times a week for another few months, and I feel confident this approach is safe.

 

The Canadian mom then forwarded a warning she received from a pharmacist at her local children’s hospital: “[Senna] is not a safe long-term option for constipation management. The rationale behind this is that sennosides, though effective now, can become less effective and even toxic to the colon if used over time. As well, sennosides can cause perianal skin breakdown.”

 

The pharmacist added: “The best data that we have suggests no more than 7 days.”

 

Seven days? Is that really what the best data says?


In support of her caution, the pharmacist attached two journal articles. These papers review several studies on middle-aged adults, including patients who had struggled with constipation for over 16 years — longer than most of my patients have been alive!


Below, I’ll discuss those papers and their relevance to children. I’ll also consider other research, including the only review article published on the side effects of long-term senna use in children, authored by doctors at Nationwide Children's Hospital, in Columbus, Ohio. 


Specifically, I’ll address the three most common concerns about regular senna use in children with chronic constipation: 1.) dependence, 2.) toxicity, and 3.) severe skin rash.


Spoiler alert: The Nationwide paper, published in 2018, concluded that the often-mentioned concern for tolerance to laxative therapy has no scientific basis.” What’s more, study co-author Mark Levitt, M.D., an expert in pediatric colorectal disorders, told me in 2025 that he has still found “no evidence to support the myth that senna is unsafe” in children, even when used for a year.


What’s more, a Chilean paper that analyzed over 30 senna studies on adults and animals found “no convincing evidence” that chronic senna use alters colon function or poses a toxic risk.


Even the American Academy of Pediatrics, which gets almost everything wrong about treating enuresis (daytime or nighttime wetting) and encopresis (chronic poop accidents), considers long-term use of senna safe for children.


Certainly, we must take abundant caution when recommending medication to children. However, I see no reason to limit senna use to anywhere near 7 days.


On the contrary, I consider senna a safe and uniquely useful tool for certain children with enuresis and encopresis, at key stages of treatment.


The way I see it, a few months of senna in childhood can save a child from decades of constipation in adulthood — and from participation, at age 50, in studies on stimulant laxatives.


Why Use Senna in Kids?


Let’s review what senna is and when this laxative is warranted for use in children.


Senna is derived from the leaves or dried pods of Senna alexandrina, a shrubby plant native to Egypt. It’s the active ingredient in Ex-Lax, Senekot, Fletcher’s, and other over-the-counter stimulant laxatives.


This type of laxative, available in the form of chocolate squares, pills, or syrup, stimulates the nerves that control the muscles of the colon. When dosed properly, senna triggers a strong urge to poop within about 5 to 8 hours.


In the United States, senna is the most commonly used stimulant laxative; bisacodyl and sodium picosulphate, effective alternatives, are commonly used elsewhere.


Stimulant laxatives differ from osmotic laxatives, such as PEG 3350 (Miralax), lactulose,

magnesium hydroxide, and magnesium citrate. Osmotics draw water in the colon, softening stool so that pooping is easier and less painful, but they don’t directly trigger a bowel movement.


Both osmotic and stimulant laxatives can play a helpful role in treating enuresis and encopresis, as I explain in the M.O.P. Anthology 5th Edition. However, for children with these conditions, I generally do not rely on laxatives a stand-alone treatment.



PEG 3350 alone often spells disaster, prolonging or worsening accidents. (See Helping Your Child Off the Miralax Merry-Go-Round.) A senna-only regimen has better odds of working but is usually less effective than an enema-based regimen such as the Modified O’Regan Protocol (M.O.P.). and drags out treatment by several months or more.


Compared to senna, enemas generally do a better job of fully evacuating the rectum, and dosing Ex-Lax can be tricky. Under-dosing senna does nothing whereas taking too much can trigger poop explosions. In addition, senna often causes cramping or nausea. Many of my patients prefer enemas to Ex-Lax, surprising their parents.


Nonetheless, stimulant laxatives play a unique and significant role in constipation treatment, especially for kids with a deeply ingrained tendency to delay pooping (aka “withholding”).



Dosed sufficiently, senna stimulates a strong enough urge that children simply cannot override it. Also helpful: The urge strikes several hours after it’s taken (whereas an enema works within 10 minutes), so senna compels children to stop what they’re doing and find a toilet. This scenario, repeated daily, helps kids regain the habit of responding to their body’s urge to poop.


How often do my patients take stimulant laxatives? That depends.


Some kids take senna daily in conjunction with a daily enema — that’s the M.O.P.x regimen described in the Anthology. The goal of M.O.P.x is to evacuate the rectum twice a day. For children who are clogged enough to have accidents, particularly daytime pee or stool accidents, pooping twice a day is usually needed to make a dent in the stool pile-up that is the root cause of accidents.

 

Once accidents stop, whether this takes a few weeks or several months, children on M.O.P.x

gradually taper off Ex-Lax and enemas. Early in the taper process, some kids need Ex-Lax on their enema-free days, though others are able to poop spontaneously simply with the help of osmotic laxatives.

 

Few of my enuresis/encopresis patients who take Ex-Lax need it on a daily basis for more than a few months. Most taper off Ex-Lax completely within six months, though they may keep it as a tool in their back pocket to use periodically.

 

In my experience, 7 days of senna won't accomplish much of anything.

 

Do Children Build an Unhealthy “Tolerance” to Ex-Lax?


The Canadian pharmacist mentioned earlier insisted that senna “can become less effective . . .  if used over time” — i.e., children require more and more senna to poop. Many providers believe children who use Ex-Lax regularly become dependent on it, developing an inability to poop on their own.


I disagree. Here’s the thing: Children who need senna already can’t poop normally. Over time, the accumulation of stool has stretched their rectum, compromising its sensation and tone. If these kids could fully evacuate their rectum daily, as is healthy, they would not need senna in the first place! But without the temporary help of laxatives and/or enemas, these kids can’t even feel the urge to poop.


Where do the “tolerance” and “dependence” ideas come from?


In my experience, three different scenarios can give a false impression of tolerance:


•Scenario #1: Let's say a severely constipated child takes enough daily Ex-Lax to stimulate a bowel movement. With continued daily senna, the rectum will start to empty but will remain enlarged, floppy, and weak. It takes a good three months for a dilated rectum, once cleared out, to bounce back. So, during that healing period, it may take even more Ex-Lax to trigger a bowel movement. A floppy rectum just can't squeeze well.


In my experience, three different scenarios can give a false impression of tolerance:


•Scenario #1: Let's say a severely constipated child takes enough daily Ex-Lax to stimulate a bowel movement. With continued daily senna, the rectum will start to empty but will remain enlarged, floppy, and weak. It takes a good three months for a dilated rectum, once cleared out, to bounce back. So, during that healing period, it may take even more Ex-Lax to trigger a bowel movement. A floppy rectum just can't squeeze well.


Or, think of it this way: It doesn't take a lot of pressure to get the toothpaste out of a full tube. But once the tube starts to empty, it takes more force. Similarly, it may take more force — that is, more Ex-Lax — to empty a floppy rectum that is not completely full.


•Scenario #2: Some children who appear to need increasingly high doses of senna weren’t taking enough senna to begin with. Ex-Lax is notoriously under-dosed. Parents hold back because, understandably, they don’t want their kids to experience cramping. However, that cramping sensation is often needed to trigger a bowel movement. Some kids will poop on 1 Ex-Lax square; other kids need 6 squares to feel the urge.


•Scenario #3: Some kids may appear to become “tolerant” because at first, the Ex-Lax-triggered urge sort of startles them into pooping. But soon, they harness their withholding super-power and manage to override that urge. At this point, they need a stronger dose. (To clarify, these kids aren’t “willful” or “stubborn.” They don’t even realize they’re overriding the urge, as it is a deeply ingrained habit.)


At any rate, these scenarios are short-lived. Over time, children who are treated appropriately for chronic constipation need less Ex-Lax, not more. Once the rectum's tone and sensation have been fully restored, children feel the urge to poop and act on it — no Ex-Lax needed.


So, sure, many of my patients “depend” on Ex-Lax (and/or enemas) to poop at the start of treatment. Their floppy rectums can’t shovel all the stool out the door, to speak. But this is not the same thing as being dependent on senna to poop the way patients with type 1 diabetes are dependent on insulin to manage their blood sugar.


All my patients are able to wean off senna completely. In the meantime, pooping with the help of Ex-Lax, even if a high dose is required over several months, is a heckuva lot healthier for a child than walking around for years with a belly load full of stool.

 

If a parent says their child has become “dependent” on Ex-Lax to poop, this tells me the child’s rectum has not fully emptied or bounced back, and more robust treatment is needed. An abdominal x-ray can confirm either scenario.

 

I know from experience that daily senna use does not cause children to become dependent on this medication. But what does the research say?

 

Well, not much. Doctors at Nationwide Children’s Hospital reviewed decades of scientific literature on long-term senna use in children, plus 3 years of patient records at their own hospital (640 children who'd used senna for, on average, over 300 days). Their conclusion: “Despite an extensive search of both the medical and lay literature, we did not find any reference to long term tolerance due to treatment, which we find is a frequently mentioned concern by families and clinicians.”

 

Of course, the fact that no study mentioned tolerance does not rule out the possibility that this phenomenon exists. No study has tested whether, over time, chronically constipated children require increasingly high doses. But to date, no scientific evidence exists to suggest children become tolerant to senna.

 

Do adults? Again, there’s a paucity of evidence. A Swedish study of 35 women, average age 50, who had used sodium picosulphate at least weekly for 10 years on average, found that while 70% of women did increase their laxative dose over time, the increase was “moderate" and of no concern. One-quarter of these woman had used stimulant laxatives for at least 20 years! I'll bet if they'd been treated aggressively for constipation as children, they never would have ended up in that study.

 

In addition, a German survey reviewed the records and questionnaires of some 1,700 pharmacy patients who took sodium picosulphate. About 90% rated the drug's effectiveness as “good” or “very good,” and 96% reported that they had not exceeded the recommended dose. The authors concluded: “There was no weakening of the efficacy rating with increasing duration of use.” In other words, patients didn’t find the laxative less effective over time, even though they had not escalated their dosage beyond recommended levels.

 

I find it hard to square any of this data with the Canadian pharmacist’s claim, so common among healthcare providers, that stimulant laxatives can become less effective “if used over time.”

 

In my opinion, any child who appears to be “dependent” on senna to poop after a few months of treatment is not being treated aggressively enough. If the child is relying solely on senna to treat enuresis or encopresis, I would recommend that child implement M.O.P. instead. If the child is already on M.O.P., I recommend switching to a more aggressive variation, such as Multi-M.O.P. or J-M.O.P. (described in the Anthology).

 

Is Senna Toxic or Carcinogenic?

 

The most serious concern about senna use in children is that medication may cause “permanent changes to the colon and its receptors,” as the Canadian pharmacist wrote.

 

To support her concern, she cited a 2019 Danish review paper of randomized clinical trials — that is, studies that randomly assign subjects to different groups in order to compare treatments (as opposed to studies that look back on previous treatments). Searching a 60-year period, the authors found just 5 studies that lasted at least 4 weeks (their definition of "long-term"). Their paper states that stimulant laxatives “are associated with harmful long-term colonic effects and possible carcinogenic risk.”

 

This statement would be concerning if true. But is it?

 

The 5 clinical trials included in the Danish review included about 1,000 chronically constipated patients, average age around 50. All 5 trials found stimulant laxatives well tolerated and quite effective. The Danish authors summed up the side-effects as “generally mild,” nothing more serious than diarrhea or abdominal pain. (Conflict-of-interest alert: Three of the trials were funded by drug companies that manufacture stimulant laxatives.)

 

The Danish authors did not articulate any worries about 4 weeks of senna use. Rather, their concerns about toxicity appear to stem largely from a 1998 retrospective study of chronically constipated patients in their 60s.

 

That study, conducted by the Cleveland Clinic Florida, compared patients who’d used stimulant laxatives for at least one year with constipated patients who did not use stimulant laxatives. Of note: Those who’d used stimulant laxatives reported suffering from constipation for 16.8 years, on average, and using stimulant laxatives for 7.9 years!

 

A total of 73 patients underwent barium enemas, a type of diagnostic x-ray. Among the stimulant laxative users, 32% were found to have lost Haustral folds. These are folds in the colon lining that play an important role in nutrient absorption. Among the patients who did not use stimulant laxatives, no loss of Haustral folds was detected.

 

Based on this finding, the Florida authors concluded: “Chronic use of stimulant laxatives may impair normal colonic function and lead to bowel dysfunction, resulting in increased laxative dependency.”

 

That strikes me as quite a leap! I mean, these patients had experienced an entire decade of chronic constipation before they even took stimulant laxatives. In other words, they already had impaired colonic function and bowel dysfunction.

 

But more to the point, with regard to “toxicity,” the authors concede that nobody knows the “functional significance” of Haustral fold loss. In other words, it's unclear if this finding matters. One-third of stimulant laxative users had lost Haustral folds; were these patients worse off, in any way, than the two-thirds of stimulant laxative users who did not lose Haustral folds or the group of constipated patients who had never used stimulant laxatives? Who knows?

 

It strikes me as an even bigger leap to suggest, as the Canadian pharmacist did, that this research has relevance for children who take stimulant laxatives for over a week.

 

To support their concern, the Danish authors also cite 1980 study titled “The fine structure of colonic submucosal nerves in patients with chronic laxative abuse.” That’s right — adults with chronic laxative abuse. Colon biopsies showed “pathological findings of the nervous tissue” in patients who abused stimulant laxatives in comparison with constipated patients who did not take laxatives.

 

Based on all the above research, the Danish researchers warn “against using stimulant laxatives for more than a month.”


I’m not buying it.


Just because studies of middle-aged laxative abusers show "pathological findings" does not mean it's risky for either adults or children to use senna for more than 4 weeks.


Furthermore, the Danish authors did not mention a lengthy 2009 review paper from the University of Chile. The Chileans reviewed over 30 studies of rodents, rabbits, dogs, and humans that considered whether senna is toxic or carcinogenic. Their conclusion: no and no.

 

They found “no convincing evidence” that chronic senna causes structural or functional changes in the nerves or smooth muscle of the colon. They also concluded senna “is not carcinogenic in rats,” even rats who ingest an incredibly high dose every day for 2 years.

 

In sum, the Chileans wrote: “The current evidence does not show that there is a genotoxic risk for patients who take laxatives containing senna extracts or sennosides.”

 

Let’s move on, briefly, to the third concern about long-term use of senna in children: breakdown of the skin surrounding the anus.

 

Yes, children can develop a serious skin rash from taking senna — for example, if they have a poop explosion and no one changes their diaper for hours. But this situation is rare and easily avoided.

 

The Nationwide Children’s Hospital review paper found eight articles reporting perianal blisters, in a total of 28 children. Two-thirds of these kids had accidentally taken chocolate senna squares!

 

In any case, all the blistering episodes were related to high-dose, night-time accidents or intense diarrhea with several hours of stool-to-skin contact. The review of Nationwide’s own patients found that 2.2% of the children who took senna long-term developed blisters. All these kids had experienced accidents overnight.

 

To avoid this situation, simply give your child senna early in the day, to ensure pooping well before bedtime. And keep chocolate senna squares out of the reach of children!

 

Bottom line: I find warnings about long-term senna use in children overblown.

 

When used judiciously, senna is a terrific tool for helping restore rectal tone and sensation, as well as the habit of pooping daily, in children with enuresis and/or encopresis.

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