By Steve Hodges, M.D.
I get a lot of questions about Ex-Lax.
Parents want to know: What's the difference between Ex-Lax and Miralax? Can Ex-Lax substitute for enemas? How much Ex-Lax can I safely give my child? How many hours does it take to kick in?
Ex-Lax is not a standard part of the Modified O’Regan Protocol (M.O.P.), the regimen I recommend for treating bedwetting and accidents. M.O.P. combines enemas and osmotic laxatives, a combination I have found resolves enuresis and encopresis better than any other treatment. However, Ex-Lax can be a helpful adjunct to M.O.P., and I have added it as an option on the M.O.P. Progression chart. For some children on M.O.P., Ex-Lax turns out to be the missing ingredient for success.
As one mom in our Facebook support group posted: “Even on M.O.P., our daughter wouldn’t ever completely empty on her own, but when we added Ex-Lax she did, and then she started having dry nights.”
For other families, Ex-Lax doesn’t help, but you won't know until you try, and in certain circumstances, I think Ex-Lax is worth trying.
Below I answer questions I commonly get about Ex-Lax.
Q: What is the difference between Ex-Lax and Miralax?
A: Ex-Lax and products such as Senekot are stimulant laxatives. These products, derived from the senna plant, stimulate the intestinal muscles to contract and squeeze out idle poop.
By contrast, Miralax, a brand name for PEG 3350, is an osmotic laxative, a type of laxative that draws water into the colon to make poop mushier and help it slide through.
Other — and less controversial — osmotic laxatives include magnesium citrate (such as Natural Calm), lactulose (a prescription liquid), magnesium hydroxide (Milk of Magnesia and Pedia-Lax chewable tablets), and magnesium oxide (such as Mag-Go Kids).
Osmotic laxatives are not habit forming and are part of the daily M.O.P. regimen, second in importance to enemas.
According to the conventional wisdom, stimulant laxatives are habit forming and should be used sparingly; I, myself, have repeated this "wisdom," having heard it from pediatric gastroenterologist colleagues.
However, I have not found any scientific evidence to support this notion, and neither did a recent review article conducted by a team at Nationwide Children's Hospital, in Columbus, Ohio, and published in the Journal of Pediatric Surgery. The article, which reviewed eight studies on senna safety in constipated children, found "no evidence of tolerance."
And after much discussion with pediatric GI docs I trust, including one of the co-authors of the review article, I've come to believe that constipated children who use Ex-Lax do not actually become dependent on this medication to poop and that Ex-Lax is not habit-forming any more than enemas are — which is to say, not at all.
Certainly you would not want to give Ex-Lax (or enemas) to any person, adult or child, who is not constipated. But I believe that, as with enemas, Ex-Lax will only help clean out the child's rectum and help the child overcome the withholding habit. At that point, the medication simply becomes unnecessary.
Q: If my doctor is opposed to enemas, can I use Ex-Lax as a substitute?
A: Not in my opinion. Though Ex-Lax does not seem to be habit forming, I believe enemas do a better job of cleaning out the rectum. I recommend Ex-Lax primarily as an extra tool for children who are on M.O.P. or who have completed protocol.
If your doctor believes enemas are risky or unsafe, I recommend handing him or her “The Physician’s Guide to M.O.P.” In this free download, I explain to colleagues why I consider enemas critical to resolving enuresis and encopresis.
Q: For children on M.O.P., how can Ex-Lax can be useful?
Parents of my Wake Forest clinic patients, as well as parents in our support group, have reported that Ex-Lax helps in these situations:
•When a child is on M.O.P. or M.O.P.+ — and even Double M.O.P. — but still has not achieved the all-important “spontaneous poop.”
One mom in our support group posted: “Ex-Lax is helping my son feel when he needs to poop. M.O.P. helped us eliminate poop accidents, but he never would self-initiate.”
Another mom posted: “Ex-Lax was the only change that brought my daughter to a clean X-ray.”
This girl took Ex-Lax in conjunction with Double M.O.P., a regimen that involves overnight oil-retention enemas followed by regular enemas in the morning. (Yes, that combination is safe, as olive oil and mineral oil enemas simply soften stool; they do not stimulate the colon.)
Her mom notes that the first time the girl took Ex-Lax, “it caused diarrhea, and she pooped four times.” But after that, Ex-Lax did not prompt her daughter to self-initiate pooping “and only produced poop on scheduled potty sits.”
•When a child is on Phase 2 or Phase 3 of M.O.P. — in other words, tapering from daily enemas — and goes a day without pooping.
A child who achieves dryness on M.O.P. but still has not achieved a daily spontaneous poop is a prime candidate for relapse. Some families who have learned this on the first go-around have been able to prevent relapse by adding Ex-Lax to the regimen on days when the child does not poop.
I recommend this only as a temporary situation. By the time children finish Phase 3 of M.O.P., they should be pooping on their own daily.
•When a child on M.O.P. goes on vacation, and enemas are too difficult to maintain.
It may not be realistic for a child to have enemas while on a trip, and that’s OK!
For a week or two, Ex-Lax may be the next best thing. During a vacation, it’s also important for the child to maintain the daily dose of osmotic laxative.
Q: What are possible side-effects of Ex-Lax?
A: Stomachache, cramps, diarrhea, and nausea are among the most commonly reported symptoms. Often these symptoms subside when the dose is reduced, even by ¼ square.
A far more rare symptom is blistering in the perineum (around the anus). The team at Nationwide Children's Hospital found that among its own patients prescribed senna, 2.2% developed blistering and "all blistering episodes were related to high dose, night-time accidents, or intense diarrhea with a long period of stool to skin contact."
The children who experienced blistering took, on average, more than 60 mg of senna daily, equivalent to four squares of Ex-Lax.
Q: How many hours does it take Ex-Lax to kick in?
A: Often 8 to 10 hours, but that depends on the child. For some kids, it works more quickly.
One mom posted that her 6-year-old daughter would take Ex-Lx around 7 a.m., “and around 2:30 p.m. the feeling would hit her.”
Another mom posted that she gives her 4-year-old Ex-Lax in the evening, and her daughter poops after breakfast.
I suggest experimenting with Ex-Lax on the weekends rather than on a school day. See how long it takes to work on your child, and then time the medication so the child will be at home, rather than at school, when the urge to poop kicks in.
Q: How much Ex-Lax is safe for children to take?
A: I urge patients to start by following the instructions on the Ex-Lax label: 2 squares, either once or twice a day for children 12 and older (so, a maximum total of 4 squares), and 1 square once or twice a day for children (maximum 2 squares) for kids ages 6 to 11. The label says to consult your doctor if your child is under 6. For these kids, I generally advise starting with 1/2 or 1 square per day.
Keep in mind these are general ranges. You have to experiment with what works for your child. Many children on M.O.P. take ¾ square or 1 ½ squares once or twice a day or squares. Some kids take 6 squares a day, with good results and no side effects. I think this is OK for a few weeks or periodically.
As with dosing osmotic laxatives and enemas, Ex-Lax dosing requires trial and error.
Q: I’m afraid to give my son more than 1 square of Ex-Lax per day because I worry he’ll have a poop accident at school due to urgency. Is this a realistic concern?
A: I suggest trying it on the weekend first, so you can get an idea of how long it takes for Ex-Lax to work on your son. If you're worried, have him take it after school.