Coming soon: AboutKidsHealth is getting a new look! Learn more Watch a video tour

Functional constipation: Your child's treatment plan

What is functional constipation?

The re​ctum has two sets of muscles - the internal and external anal sphincters - that allow stool (poo) to pass out of the body. You are not able to control the muscles of the internal anal sphincter, but you can control the muscles of the external anal sphincter.

When stool enters the rectum, the muscles relax in the internal anal sphincter. A person has an urge to pass stool when it reaches the external anal sphincter.

If your child relaxes the external sphincter as they should, stool can leave their body. If they have functional constipation, however, they will withhold their stool. They do this by tightening their external sphincter and the muscles in their bottom, known as gluteal muscles. This action pushes stool back into their body and makes them lose the urge to pass stool.

What are the signs of functional constipation?

You might recognize the signs of functional constipation if you see your child regularly:

  • ​squatting
  • rocking
  • walking stiffly on their tiptoes
  • crossing their legs
  • sitting with their heels pressed against their perineum (the area just in front of their anal opening).

Is functional constipation harmful?

When your child withholds stool, their rectum and lower colon can stretch. This can lead your child to keep in stool much longer than normal. The longer the stool remains in the rectum, the more water it loses and the harder it becomes. The stool can then become "impacted" or packed into the rectum.

At the same time, your child's rectum can only hold onto a certain amount of stool. If the stool is impacted in the rectum, your child may experience accidental overflow soiling. This is when a small amount of stool leaks out into the underwear. Naturally this can be distressing both for you and your child.

How is functional constipation treated?

If your child has functional constipation along with accidental soiling, they will need to follow a treatment plan. The goal of this treatment is for your child to have a smooth, easy-to-pass, large bowel movement (type 3 on the chart below) at least once a day without soiling.

Modified Bristol Stool Form Scale for Children
Get Adobe Flash player
This chart helps parents and children check for constipation or diarrhea. Stool that is a type 3 or 4 on the scale shows that the digestive system is healthy.

Your child's treatment has two phases, or parts:

  1. a disimpaction (clean out) phase
  2. a maintenance phase.

Disimpaction phase

During this phase, your child should drink lots of fluids and stay near a toilet. Make sure that some of these fluids include water and drinks containing electrolytes (such as Gatorade or other sports drinks).

To help your child empty their bowel, you will need to give them the following medicines:

  • PEG3350
  • Pico Silax.

Your child's doctor will give you a prescription for these medicines and tell you exactly how much to give your child each day. You can make a note of these instructions below.


Give ______grams _____ a day for _____ days.

Pico Silax

  • In the morning, have your child drink ____ sachet(s) diluted with 150 mL (5 oz) of water.
  • ____ hours later, have your child drink _____ sachet(s) diluted with 150 mL of water.

Maintenance phase

Once the bowels are empty, you need to continue the medicine prescribed by your child's doctor.


Give ____ grams ____ a day.

Continue maintenance for at least ______ month(s).

Does my child need to follow a special diet as part of their treatment?

No, but your child should eat a balanced diet of whole grains, vegetables and fruit. This will give your child the fibre they need to help with passing stool. You should also make sure that your child drinks plenty of fluids.

How can I stop my child withholding stool in the future?

  • Allow "toilet time" three times a day for five minutes, but do not force a new routine on your child.
  • Depending on your child's age, make toilet time as comfortable as possible by having good foot support available while your child sits.
  • Keep a record of how often your child passes stool.
  • Do not punish your child if they do not pass stool during toilet time. Instead, set up a reward system for your child when they do pass stool. The aim is to reinforce good behaviour and ignore soiling.
  • Maintain a consistent, positive and supportive attitude right through your child's treatment.

When can my child stop taking their medications?

Do not consider stopping medications until your child has been doing well for at least six to 12 months. Do not change your child's medication dose before speaking with your doctor. Your child's doctor will reduce their medication dose slowly, usually by a quarter dose every three to six months.

Points to note


  • Medications for constipation are safe as long as your doctor monitors your child. They will not make your child's bowel "lazy".
  • Follow your doctor's advice and remember that labels on the products are for general use, not for each person's individual needs.
  • Some children need the adult dose or even a higher dose of the medication for them to be able to pass stool properly.


  • You have the best chance of treating constipation by having your child empty their bowel at least once a day without rushing.
  • It is common for children to experience constipation again, even after successful treatment. Some children might have difficulty with passing stool into their teen years.


  • Soiling is accidental. It is not a sign that your child is deliberately being naughty.
  • Soiling may get worse when treatment starts and can last for 12 to 24 months.


You will only treat soiling successfully if you continue to follow up regularly with your child's doctor. For example, speak to your child's doctor if you feel your child's treatment needs to be changed.​

Key points

  • Functional constipation is not due to a medical problem. It happens when a child withholds stool, usually because they are afraid of the pain linked to passing hard stools or have a fear of the toilet.
  • Treatment involves a disimpaction phase and a maintenance phase.
  • Give your child a diet that is high in fibre, vegetables and fruit and has lots of fluids.
  • Treatment often involves medications and regular follow-up appointments for one or two years. Be patient and continue with the treatment plan advised by your child's doctor.
Katharine Williams, NP

Kimberly Colapinto, NP

Marina Strzelecki, Clinical Pharmacist 

SickKids Constipation Working Group​



NASPGHN (2006). Evaluation and treatment of constipation in infants and children: recommendations of the North American Society for pediatric gastroenterology, hepatology and nutrition. Journal of Pediatric Gastroenterology and Nutrition, 43: e1-13.

Margolis, I. (2010). Treatment of Chronic Constipation and Encopresis.

Rowan-Legg, A. (2011). Managing functional constipation in children. Paediatric Child Health, 16(10):661-665.

Lane, M., Czyzewski, D., Chumpitazi, B., Shulman, R. (2011). Reliability and validity of a modified Bristol Stool Form Scale for children. Journal of Pediatrics, 159:437-441.​