How Long Does It Take Miralax to Work on a Toddler?

Updated on October 20, 2011
D.M. asks from Somerville, MA
14 answers

My 2 yr old daughter has been very constipated for the last two days. She says it hurts to poop so her pedi suggested Miralax (once a day/half a cap full). I'm just wondering if anyone has had any experience with Miralax and most importantly how long it took for it to work. I gave her the first dose at about 1pm today. My daughter is very uncomfortable :(

What can I do next?

  • Add yourAnswer own comment
  • Ask your own question Add Question
  • Join the Mamapedia community Mamapedia
  • as inappropriate
  • this with your friends

Featured Answers



answers from Washington DC on

It can take about 2 days to start working.
If she is that uncomfortable, you can try a child's suppository. Those work within 20mins, but my daughter always made a big crying scene when we had to use them so we try not to.

1 mom found this helpful

More Answers



answers from Phoenix on

We have dealt with issues since birth and have used Miralax numerous times. Most recently after 6 days of only water passing and having a partial blockage we put him on Miralax and increased the dose every day until he went. We got up to a cap full 3 times a day and after 5 days he finally cleaned out. He is pretty severe when it comes to this stuff so I wouldn't expect your daughter to take as long. I would think you should see something by tomorrow. If you don't and she is in increasing amounts of pain please take her in and demand they do a KEB (xray of the abdomen) She could have an occlusion that even Miralax won't help. Miralax essentially draws water into the bowel/colon to assist with constipation. However, it can cause gas in some (my son is one it does). If she is completely blocked water and gas can build up behind the blockage causing more pain. I don't say this to scare you but many doctors don't give this information right away as it is rare, yet parents I feel should know what to look for and feel confident that if you don't feel something is right you should follow your instinct.

Another thing that has worked well for us and you can ask your doctor about is Magnesium Citrate. It is OTC and very inexpensive. usually used to clean out adults prior to a colonoscopy and can sometimes cause slight cramping. but it worked fast for us. I used it 2 weeks ago when he hit day 5 of no BM again....1tsp in his juice and in an hour he went. Now I just give him a little in his cup every day or two trying to get him regular. Fiber gummies never worked well for us though I know they do for many kids.

Have you tried warm baths as well? it can help the bowel relax and get things moving sometimes.

Good luck, I hope she feels better soon.

3 moms found this helpful


answers from Charleston on

About a day if she's slightly constipated, maybe longer. We had to give it to my daughter in 6 hour intervals until she went because she was so severely constipated. Stay close to home as it might cause a little diarrhea.

Keep her constantly drinking to help things "move" along. Put some bran on her cereal in the mornings, and avoid, cheese, bananas, milk, yogurt, dairy in general. The more you can get her to eat that has fiber, the better.

2 moms found this helpful


answers from Washington DC on

My sons ped suggested miralax as well. He would get pains right before he had to go. He would also go pale and have accidents. I took him off after a week and started him on Fiber gummies. I would talk to your ped about that possibility. I have him on a pretty good schedule with those and there is no constipation. Poor baby, hope she feels better soon.

2 moms found this helpful


answers from Pittsburgh on

In my experience, it took a few days. If she is really in pain because of it, go with the glycerin suppository for immediate relief (within minutes usually)and then follow up with the Miralax for at least a few days to make sure things are moving ok.

2 moms found this helpful


answers from Detroit on

My daughter is 4 and ran into some constipation issues so the pediatrician recommended Miralax. She weighs 37 lb so they did recommend starting with 1/2 capful once or twice a day. I gave it to her twice a day for 2 days before she had a BM, and then backed off to once a day - and then she had really soft stool that she had a hard time controlling. So then I stopped completely, but it got her over her fear of going poop on the potty. Now I still give it to her 2 or 3 times a week because her poops will still be big and difficult for her to pass - and she gets plenty of fruits, veggies, fiber and water. Make sure you are doing the same for your daughter, and nothing that tends to bind them up (dairy, bananas, etc.) - and that she is getting plenty of fluids too. A little prune juice might help too. Pumpkin is really good for constipation because of the fiber content - so are pears, peaches and raspberries.

2 moms found this helpful


answers from Spokane on

My son usually goes the next day.

1 mom found this helpful


answers from Kansas City on

prune juice or baby prune puree in her milk, scoop some yogurt to take the edge off. She will go sooner.

Aloe juice works wonders too.

Hope she feels better soon. She might surprise you with a blowout tonight.. :P

1 mom found this helpful


answers from Raleigh on

It took a couple of days for it work on my son. And prepare yourself for the amount that will come out that initial time. It was quite startling... lol

1 mom found this helpful


answers from Bloomington on

Wow! Half a cap!! My ped. suggested 1/4 cap for our constant constipater and she was a year older at the time.

It takes about a day, but that is a high dosage, so maybe 8-12 hours.

Our ped then suggested a daily dose of 1/4 cap, but that was too much. We've gone to just using fiber gummies each day and uping more fiber foods. She now goes every 2 days and lately almost daily. It's been a tough road!!!

Try giving her a warm bath??

1 mom found this helpful


answers from Portland on

It takes however long it takes for food to move through the digestive tract. It binds with the food and keeps it moist/soft, but it isn't a "medicine" that acts on whatever the bowel already contains. So it will take about a day or day and a half before it comes out the other end. And it may have to move hardened poop along with it, which could slow it down a bit.

Poor baby. Try to keep her playing actively – physical exercise will not only help distract her from her discomfort, but it will stimulate the bowel to keep it churning along.

If she's in real misery, consider giving her a liquid glycerine suppository made especially for children. It will probably prompt a bowel movement within an hour, sometimes even minutes. The action can be a little harsh, but then the discomfort will be finished. These have worked very well for my grandson (use only occasionally as an emergency back-up), and although he hates being given the suppository, he admits it helps a lot.

Be sure to keep giving her the Miralax daily for awhile to make sure she doesn't develop long-term problems.

1 mom found this helpful


answers from Dover on

It took our daughter 4 days for things to "work themselves out."



answers from Johnson City on

I use dark karo, usually works within hours mix it in somethin good to drink



answers from Charlotte on

3 days but then you use it daily and she will go daily

For Updates and Special Promotions
Follow Us

Related Questions