Constipation in Children
Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management
Definition
Constipation in children is a common condition characterised by infrequent, painful, or difficult defecation, often associated with stool withholding behaviour.
Aetiology
- Functional constipation: most common, often due to dietary or behavioural factors.
- Organic causes: less common, includes Hirschsprung’s disease, hypothyroidism, coeliac disease, and spinal abnormalities.
- Medication-induced: opioids, anticholinergics, iron supplements.
- Psychological factors: fear of painful defecation, toilet training issues, changes in routine.
Pathophysiology
- Delayed colonic transit results in excessive water absorption from the stool, leading to hard, dry stools.
- Withholding behaviours (e.g., crossing legs, clenching buttocks) further exacerbate constipation.
- Chronic retention can lead to rectal dilation, reducing the sensation of the need to defecate.
Risk Factors
- Low-fibre diet.
- Inadequate fluid intake.
- Delayed or difficult toilet training.
- Previous painful defecation.
- Emotional stress or anxiety.
- Family history of constipation.
Signs and Symptoms
- Infrequent bowel movements (<3 per week).
- Hard, dry stools that are difficult to pass.
- Straining, pain, or discomfort during defecation.
- Abdominal pain and bloating.
- Faecal soiling (encopresis) due to overflow incontinence.
- Rectal bleeding due to anal fissures.
Investigations
- Clinical diagnosis: based on history and symptom assessment.
- Abdominal examination: palpable stool mass in the lower abdomen.
- Digital rectal examination: rarely required but may be done if Hirschsprung’s disease is suspected.
- Further tests: thyroid function tests, coeliac serology, or spinal imaging if organic cause suspected.
Management
1. First-Line Management:
- Dietary modifications: increase fibre intake (fruits, vegetables, whole grains).
- Hydration: encourage adequate fluid intake.
- Toilet training: establish a regular toileting routine, encourage sitting on the toilet after meals.
2. Pharmacological Treatment:
- First line laxative: macrogol (e.g., Movicol) for faecal disimpaction and maintenance.
- Second line: lactulose if no response to macrogol.
- Ongoing treatment: continue laxatives for several months and wean gradually once normal bowel habits are established.
3. Referral:
- Paediatrics: if red flags suggest an underlying organic cause (e.g., failure to thrive, delayed passage of meconium, abnormal neurology).
- Dietitian: if significant dietary intervention is required.
- Psychology services: if behavioural issues are a contributing factor.