Background
Constipation is defined as hard stools that are difficult to pass. Defaecation may be painful and may be less frequent than normal. There is a wide range of normal stool frequency: normal breast fed infants may have a stool following each feed or only one every 7- 10 days. Bottle fed infants and older children will usually have a bowel action at least every 2 to 3 days.
Constipation may be associated with abdominal pain, reduced appetite and irritability. Vomiting is rarely a sign of constipation alone. Children may develop constipation as a result of:
- natural tendency to reduced gut motility
- a poor diet
- a toddler behaviour pattern
- inadequate fluid intake (? acute illness)
- reduced activity
- painful anal conditions eg. fissures
- sometimes following sexual abuse
- Organic causes are rare after early infancy
Assessment
All infants under 3 months should be discussed with the registrar or consultant. They may require referral for exclusion of Hirchsprung’s disease. Suggestive symptoms and signs include delayed passage of meconium, vomiting, failure to thrive, abdominal distension and a positive family history.
Do not perform a rectal examination - it is rarely helpful and usually traumatic to the child. An inspection of the anus is important to exclude painful conditions. Acute anal fissures are generally posterior and may occur after passage of a large stool or may complicate inflammation of the perianal skin eg. in pinworm infestation. Perianal cellulitis is caused by group A streptococcal infection and is characterised by induration and marked erythema of the perianal skin with mucopurulent exudate.
An abdominal x-ray is not helpful in the initial assessment and should not be ordered.
Remember that urine infections are more common in constipated children and should be sought if symptoms are suggestive (see UTI guidelines).
Management
Carers need to be reassured about the safety of laxatives in children* Rectal medications should be avoided in the first instance and not prescribed without discussion with the consultant.
Management Steps
Step 1
- high fibre diet
- adequate fluid intake
- adequate exercise
- regular toileting
- Provide parent handout and go through these aspects in detail with parents
Step 2
- Use laxatives - a faecal softener and an aperient
- Suggested starting regime:
- Lactulose (< 5 years 5 ml bd, > 5 years 10 ml bd). and
- Sennakot granules: (2-6 years: 1/2 teaspoon nocte, 6-12 years: 1 teaspoon nocte)
- Abdominal pain may occur as a side effect
- Increased doses may be required in some children with chronic constipation
- The dose should be titrated to achieve at least one soft stool per day
- Children may be given up to 25ml of lactulose or parachoc per dose
- The maximum daily dose of sennakot granules should be 3 teaspoons per day
- If overflow incontinence is present warn families that it may worsen initially with treatment
Step 3
- Rarely patients may require admission to achieve bowel emptying
- Treatment will involve a bowel preparation agent either Picolax sachets (sodium picosulphate 10mg, magnesium oxide 3.5mg, citric acid 12.0g, aspartame 36mg; <2 years - 1/4 sachet, 2-4-years - 1/2 sachet, 4-9 years - 3/4 sachet, repeat in 6 hours if no response) or colonic lavage solution (eg. Golytely: orally or via a nasogastric tube)
- Chronic constipation can result in faecal overload, overflow incontinence and considerable secondary emotional and behavioural difficulties
- Chronic faecal retention causes rectal dilatation, reduced sensation of fullness and sphincter disturbance such that soft stool percolates down from the proximal colon and is passed without control
- Encopresis or soiling is usually the result of constipation
- Treatment needs to continue for a sufficient length of time for colonic size and sensation to return to normal
- Many children will require months of treatment
Disposition
All patients should be referred for follow up to a general practitioner or a general paediatric clinic within 7 to 10 days.