Laxatives

Laxatives

Laxatives are medications that help the body to get rid of poo. They are a standard and essential part of the treatment of constipation and have been shown to speed up improvement better than dietary changes alone.

What are they?

In the treatment of constipation, the aim is for 1 soft but formed poo each day. Until the body can manage that alone, it will need help (from laxatives).

Laxatives are medications that help the body to get rid of poo. They are a standard and essential part of the treatment of constipation and have been shown to speed up improvement better than dietary changes alone. Most are available over the counter at a pharmacy but advice about dosage from a nurse or doctor is helpful.

How do they work?

There are 2 main ways in which laxatives for childhood constipation work:

  • some soften the hard poo and make it easier to pass (poo softeners)
  • some help the bowel push the poo out (stimulants or emptiers)

Which laxatives are available?

Some laxatives that are available for the treatment of constipation are listed below. There are regular changes to the brands which are fully or partially subsidised on prescription. Please check the information below with your doctor or pharmacist.

If a laxative is fully subsidised on prescription, it means there will be no charge for the medicine (although you may have to pay a prescription charge). If a laxative is partially subsidised, there will be a part charge to pay. You may also have to pay a prescription charge. This will depend on several factors, including the age of your child and whether you have a Community Services Card.

For information about the costs of medicines in New Zealand see:

Poo softeners

  • lactulose (Laevolac)
    This laxative comes as a liquid and is the most common and well tolerated medication used for constipation in children. It may taste better if you chill it or mix it with some juice or milk from home. Laevolac is the only brand fully subsidised on prescription
  • liquid paraffin / mineral oil
    This works by lubricating and softening the poo; too much, however, can make the poo very oily. It tastes best if you mix it with some chocolate milk or orange juice from home and then chill it before giving it to your child. This is not subsidised on prescription but is available over the counter at pharmacies. It can be quite expensive so it may be worth comparing a few prices
  • docusate / poloxamer (Coloxyl or Laxofast)
    This laxative comes as a capsule, tablet or drops (which are most suitable for children under 3 years of age) and is useful in babies and in children with mild constipation. This laxative is fully subsidised on prescription

A poo softener which is fully subsidised in some circumstances (your doctor will need to apply for a special authority to have it funded on prescription):

  • macrogol 3350 (Movicol or Lax-sachets)
    This laxative comes as a powder which is mixed with water and can be flavoured with cordial if needed. It is particularly good for children with very hard or impacted poo. This laxative is only subsidised on prescription in certain circumstances, such as when your child has had ongoing constipation despite using other laxatives

Other poo softeners which tend to be used infrequently only after other laxatives haven't been effective:

  • docusate and senna (coloxyl with senna)
    This comes as a tablet. As well as being a poo softener, it works as a mild stimulant. It is not subsidised on prescription
  • magnesium hydroxide mixture (Milk of Magnesia)
    As well as being a poo softener, this works as a mild stimulant. It is fully subsidised on prescription. Pharmacists need to manufacture the mixture so it may not be quickly available. It is an old fashioned remedy which is very effective in small volumes. Tastes better when mixed with chocolate sauce from the supermarket.

Stimulant laxatives

These are useful for treatment of constipation in some situations but are not recommended for long term use unless under medical supervision.

  • sennoside B (Senokot)
    This comes as a tablet. Your child may have diarrhoea or stomach cramps if the dose is high. Giving senna at night may reduce cramping and encourage a poo in the morning. Senokot is partially subsidised on prescription - there will be a part charge for this laxative
  • bisacodyl (Lax-tab or Dulcolax)
    This laxative comes as a tablet and suppository. Lax-tab brand is fully subsidised on prescription

Other treatments

  • sodium picosulphate + magnesium oxide + citric acid (Picoprep)
    This should only be used under medical advice. It comes in a powder which is mixed with water which can be flavoured or a concentrated liquid. It is useful for children with hard or impacted poo, if used over a few days to clear out the bowel. It needs to be followed by drinking plenty of water. It is not subsidised on prescription and is not recommended for ongoing daily use.
  1. ESPGHAN and NASPGHAN. 2014. Evaluation and treatment of functional constipation in infants and children: Evidence-based recommendations from ESPGHAN and NASPGHAN.
    http://www.naspghan.org/files/documents/pdfs/position-papers/Constipation_Feb_2014.pdf [Accessed 14/05/2015]
  2. Royal Children's Hospital, Melbourne. Clinical Practice Guideline: Constipation.
    http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=11659 [Accessed 14/05/2015]
  3. National Institute for Health and Clinical Excellence, U.K. May 2010. Constipation in children and young people.
    http://www.nice.org.uk/guidance/CG99 [Accessed 14/05/2015]

The content on this page was originally developed in consultation with:

  • The Royal Children's Hospital (Melbourne) Kids Health Info. Adapted October 2006 by Child Development Centre, Waikato Hospital
  • Paediatric Department, Christchurch Hospital
  • Paediatric Department, Nelson Hospital

This page last reviewed 24 June 2015.
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