Chronic Constipation
Background
Chronic constipation is defined as the occurrence of 2 or more of the following within the previous 8 weeks:
-
< 3 bowel motions per week
-
>1 episode of faecal incontinence per week
-
Large stools in rectum or palpable on abdominal examination
-
Retentive posturing and withholding behaviour
-
Painful defaecation
Reported in up to 28% of children
Most common scenario is painful or frightening defaecation leading to apprehension about defaecation, retention, passage of hard retained stool and a cycle of withholding and passage of hard stool.
Organic causes rare:
-
Dairy protein intolerance can manifest as constipation in first 3 years of life.
-
Hirschsprung's disease usually causes failure to pass meconium in first 48 hrs of life, and virtually never causes faecal soiling.
-
Other rare organic causes include poor colonic transit and motility, coeliac disease, hypothyroidism, hypercalcemia and spinal cord problems.
Constipation of early infancy:
-
Dyschezia (a healthy infant, straining and crying before passing soft stool) is normal but can be mistaken for constipation.
-
True constipation is sometimes associated with anal fissures, weaning or dairy protein intolerance.
Diet:
-
There is little evidence to support dietary fibre having a primary role in causing or treating childhood constipation and nothing to causally implicate lack of fluid.
-
Inappropriate emphasis on diet and fluids serves to lay the blame on the child or parents, while deflecting attention from treatments that work.
Assessment
History
-
Passage of meconium after first 2 days of life
-
Painful or frightening precipitant
-
Apprehensive behaviour such as toilet refusal, hiding while defaecating.
-
Faecal or urinary incontinence, day or night
Physical examination
-
Abdominal examination for faecal loading
-
Failure to thrive
-
Lower back, neurological assessment of lower limbs.
-
Rectal examination and abdominal x-ray do not change management and should not be performed routinely
Management
-
Aim to empty the bowel, keep it empty and provide soft lubricated stools for a long period, usually many months to years.
-
Per-rectum treatment with suppositories or enemas may add to the problem, and should be avoided. If using medications PR in the emergency setting, sedation with N2O or midazolam should be strongly considered.
A. Disimpaction (for severe symptoms):
For children:
-
A stool softener such as paraffin oil is usually first line treatment- (see table)
-
Enemas are only suitable for children with acute severe rectal pain or distress related to faecal impaction. Sodium citrate 5ml enemas (Microlax", Fleet micro") or sodium phosphate enemas (Fleet", Travad") can be used
-
For children refusing oral medication: macrogol/ electrolyte solutions (Colonlytely", Glycoprep") 1-3L/day, via NGT
(NOTE: during therapy with these agents, normal maintenance oral fluids should be given to maintain hydration. Macrogol/ electrolyte solutions provide no net fluid input and there is a risk of dehydration)
For infants <6 months:</em/>
-
Infant Glycerol suppository up to once daily
B. Follow on treatment:
For children:
-
Long term approach is needed; may take many months to years.
-
Behaviour modification
-
Regular toileting (where possible), 3 times/day for 3-5 minutes.
-
Reinforce desired behaviour with stickers on an age-appropriate chart.
-
-
Paraffin Oil 20-25 ml/day or Movicol-Half" 1 sachet/day. Gradual withdrawal should occur only when defecation has been effortless for many months.
For infants <6 months: </em/>
-
Consider prune juice, Coloxyl drops", or paraffin oil mashed into solids (>6 months and on solids).
-
Consider change to hydrolysed formula (eg. Pepti-Junior", Neocate").
Notes
Follow up:
-
Arrange follow up in General Medical clinic or with a General Paediatrician
-
Refer to Continence Clinic or Encopresis Clinic for faecal/urinary incontinence, suspected organic cause, complex or difficult cases.
Other resources:
