Constipation

Common, Gastro, General paediatrics, OPD, Psychology

Consider constipation if:

  • episodes of faecal incontinence (stains or smears in pants, potentially larger accidents),
  • retentive posturing (standing or sitting with their legs straight and stiff or crossed legs, some will sit on their own heel),
  • occasional massive but soft stools that virtually obstruct toilet.

Not just hard painful infrequent stools! Beware also dyschezia, where baby appears to strain at stool but not actually hard/large.

In a population-based prospective birth cohort, where dietary types were extracted from questionnaire, adherence to a ‘Western-like’ dietary pattern was associated with a higher prevalence of constipation up to 48 months [aOR 1.39; 1.02-1.87], which was not mediated by overweight or sedentary behaviour. Adherence to a ‘Health Conscious’ dietary pattern was only associated at short term, with a lower prevalence of constipation at 24 months (aOR; 0.65; 0.44-0.96). This suggests that specific dietary patterns in early childhood could be associated with higher or lower risks for constipation, but these effects are time-dependent. [Maternal & Child Nutrition. 9(4):511-23, 2013 PMID: 22288911]

Straining is not a criteria, in NICE, interestingly, although it is in Rome III criteria!

Red flags:

  • multiple anal fissures,
  • gross abdo distension,
  • tenderness with guarding,
  • abnormal lumbosacral or lower limb findings,
  • failure to thrive
  • etc

NICE recommends Movicol (macrogol) as first line, combining with a stimulant (picosulfate, biscodyl, senna) as second line. If macrogol not tolerated, use stimulant +/- softener (lactulose, docusate).

Warn that pain and soiling gets worse before getting better!

Review of adherence and dose important.

Toilet training eg diary, reward system, regular post prandial sitting 5 mins +/- feet on hard surface eg stool.

“Poo should be as soft as toothpaste and should come out like a snake” (Snakes and ladders booklet, Kidney Kids Scotland). Tell your teacher if no toilet paper/soap or broken seat/locks etc.

Soiling

Typically, episodes of soiling (large and small) are due to overflow of liquid stool past a large impacted stool in the rectum.  The child is unable to control, due to the distortion of the rectum.

However, children often try to deny being aware of soiling, despite the obvious smell or discomfort – this is simply a coping method, and normal sensation is usually easy to demonstrate.

The diagnosis is easier in the presence of a large suprapubic mass, or a rectal mass on digital examination.  Some children however soil for attention, without any bowel or rectal disorder.

The presence or implication of a large rectal mass requires disimpaction – an escalating regimen of a paediatric formulation of macrogol (Laxido or Cosmocol are cheaper than Movicol) as per NICE guideline 99 (doses and licensing may differ from product literature):

  • Child under 1 year: ½-1 sachet daily (non-BNFC recommended dose)
  • Child 1-5 years: 2 sachets on 1st day, then 4 sachets daily for 2 days, then 6 sachets daily for 2 days, then 8 sachets daily (non-BNFC recommended dose)
  • Child 5-12 years: 4 sachets on 1st day, then increased in steps of 2 sachets daily to maximum of 12 sachets daily (non-BNFC recommended dose)
  • If macrogol not tolerated, use stimulant laxative eg picosulfate +/- lactulose

If no progress after 2 weeks add stimulant laxative eg senna, picosulfate, bisacodyl, docusate.

Enemas eg citrate can prevent megarectum where prolonged medical treatment fails.

Polyethylene glycol licensed for distal intestinal obstruction!?

Maintenance

I suggest half disimpaction dose for maintenance.

Preferred treatment is paediatric formulation of macrogol (Laxido or Cosmocol are cheaper than Movicol) as per NICE guideline 99 (doses and licensing may differ from product literature).

  • Child under 1 year: ½–1 sachet daily (non-BNFC recommended dose)
  • Child 1–6 years: 1 sachet daily; adjust dose to produce regular soft stools (maximum 4 sachets daily) (for children under 2, non-BNFC recommended dose)
  • Child 6–12 years: 2 sachets daily; adjust dose to produce regular soft stools (maximum 4 sachets daily)
  • If macrogol not tolerated, use a stimulant laxative eg sodium picosulfate (5mg/5ml, NICE recommended doses):
    • Child 1 month to 4 years: 2.5–10 mg once a day
    • Child/young person 4–18 years: 2.5–20 mg once a day
    • Add lactulose or docusate if stools hard

.At least 3/12 of maintenance before weaning if disimpaction required initially.

I always highlight that laxative use does not induce dependency, rather, that chronic constipation is unlikely to improve without adequate treatment.

Review regularly – symptoms, toileting, taking medication.

Continue maintenance treatment until regular bowel habit established for at least a few weeks or until toilet trained. Do not stop dose abruptly.

General advice re balanced diet including fruit, vegetables, high-fibre bread/breakfast cereals, baked beans, regular toileting, exercise, sufficient fluid intake (1000-1400ml age 4-8yrs, 1200–2100ml age 9–13yrs).

Involve Health Visitor in pre-school group.

Consider trial of milk exclusion (to rule out cow’s milk protein allergy if intractable (ESPGHAN 2023).   Coeliac disease, hypothyroidism, cystic fibrosis, Hirschsprung’s disease and hypercalcaemia also come into the differential.

Surgery

Rectal biopsy indicated if delayed meconium at birth (ie >48hrs), Downs, enterocolitic episodes.

Anal fissures have high spontaneous healing rate with medical treatment.

Manual evacuation under GA may be required if resistant. No benefit on RCT for anal dilatation. Small RCT found botox as good as internal sphincter myectomy for refractory constipation.

Appendicostomy or caecostomy antegrade colonic enema (where bowel irrigated using catheter) has a role in refractory cases after age 6yrs. QOL, continence improve but appreciable morbidity.

Relapses more common in boys, under age 4, background of psychosocial or behavioural probs, encopresis. 1/3 of post pubertal children continue to have severe problems.  See also parenting and constipation.

Parent information

ERIC website – www.eric.org.uk

[NICE clinical guideline 99 – constipation in children and young people (Published 2010)]

[BMJ 2012]