Constipation is common in children and can present at three important stages of childhood, in infants at weaning, in
toddlers acquiring toilet skills and at school age.
Definition of constipation in children
The diagnostic criteria are different to those of adults. There have been various attempts to define chronic constipation
in children and the most commonly adopted is the Rome III criteria (see opposite)4,5
- The most common cause for constipation in children is functional (90-95%)
- Most children with constipation are developmentally normal
- Performing a thorough history and examination is sufficient to diagnose functional constipation in
Many conditions may pre-dispose children to constipation including ADHD, autism, coeliac disease, cystic fibrosis, dehydration,
metabolic conditions, psychological conditions and dietary factors.
Investigation of constipation in children
Careful questioning about the frequency of stooling is important, as well as the shape and consistency of the stool.
Infants under six months often strain or become distressed when stooling (dyschezia), which in a healthy infant can
be considered normal, and should not be mistaken for constipation.
Some older children may also withhold defaecation, which causes the stool to become hard and defaecation painful. This
compounds the problem and the constipation may reach a stage where there is overflow incontinence.
- Growth parameters should be checked to ensure there is normal growth
- Abdominal examination should check for distension and palpable stool particularly in the left lower quadrant and lower
- The perianal area should be checked for sensation, anal fissures and the position of the anus
- Rectal examination is controversial. It will confirm constipation if the rectal vault is full of firm stool and it
does allow assessment of anal tone, however it is invasive
- Occasionally an abdominal x-ray is useful to confirm significant faecal retention
- Rectal biopsy and rectal (balloon) manometry are the only tests that can reliably exclude Hirschsprung's disease
The data for effectiveness of the various treatments (fibre, biofeedback, behavioural modification, laxatives) for constipation
in children is not robust.
Initially dietary measures may be tried if constipation is not too severe or longstanding. Increasing fruit and vegetable
consumption as well as drinking plenty of fluids may be useful. Regular toileting after dinner, by sitting on the toilet
for five minutes, may establish a habit and provide the opportunity for daily bowel evacuation, taking advantage of the
If general measures are not helpful, laxatives will be required and treatment may be necessary for several months or
years depending on the severity and duration of symptoms.7 Once
regular bowel function has been restored, laxatives can be gradually withdrawn but relapse may occur. It is therefore
important to inform parents of this and explain that progress can be slow.
For significant faecal impaction, the use of a short course of glycerine suppositories for infants and enemas for children
(e.g. microlax) may help to dislodge the stool, allowing laxatives to work more effectively and faster.
Lactulose is commonly used in children and the dose can be split into two divided doses if there is an increase in bloating
Suggested initial doses of lactulose in children (adjust according to response):7
|1 month-1 year
10 years and above
|2.5 mL twice daily
5 mL twice daily
10 mL twice daily
15 mL twice daily
If osmotic laxatives or softeners fail to resolve the constipation, the addition or substitution of a stimulant laxative
(senna or bisacodyl) may be required, but their chronic use is controversial and they are best prescribed on the advice
of a paediatrician. Prolonged use of stimulant laxatives can give rise to atonic colon and hypokalaemia and consequently
it has been suggested that they are used intermittently to avoid impaction.7
Macrogols (e.g. Movicol) are effective both for faecal disimpaction and also as maintenance therapy for constipation
that is difficult to manage.
Referral to a paediatrician should be considered when treatment fails, when there is concern that there is organic disease
or if management is complex.
"It is important that constipation and faecal retention are recognised early as treatment may be less prolonged. When
a child reaches the stage of soiling, treatment is likely to be much more prolonged, than parents expect. Slowly down
titrating the lactulose dose is important as relapse is not uncommon."