Managing Toddler Constipation on Lactulose and Colace
Polyethylene glycol (PEG) should replace both lactulose and Colace as the primary treatment for toddler constipation, as it demonstrates superior efficacy and tolerability compared to lactulose, while docusate (Colace) lacks evidence of effectiveness in pediatric constipation. 1
Why Change the Current Regimen
Docusate (Colace) Should Be Discontinued
- Docusate is not recommended for pediatric constipation as it functions only as a stool softener without addressing the underlying motility issues that cause functional constipation in children 2
- No high-quality evidence supports docusate's effectiveness in treating childhood constipation, and it is notably absent from evidence-based treatment algorithms 3, 1
Lactulose Has Limited Efficacy
- Lactulose is less effective than other osmotic laxatives at increasing defecation frequency in children 1
- While lactulose is FDA-approved for toddlers (initial dose 2.5-10 mL daily in divided doses), it produces softer stools but does not achieve the same treatment success rates as PEG 4, 5
Recommended Treatment Algorithm
First-Line: Switch to Polyethylene Glycol (PEG)
- PEG achieves significantly more treatment success than all other laxatives (pooled relative risk 1.47, meaning 47% better outcomes) 1
- PEG is effective and well-tolerated in children over 6 months of age 6
- Start with age-appropriate dosing and titrate to achieve 2-3 soft, non-forced bowel movements daily 7
Check for Fecal Impaction First
- Before starting maintenance therapy, rule out fecal impaction through physical examination, especially if the child has paradoxical diarrhea (overflow around impaction) 7
- If impacted, perform disimpaction using high-dose PEG for the first few days or consider phosphate enemas with appropriate pre-medication 7, 6
Maintenance Phase
- Continue PEG at a sufficient dose for months to years, as 40-50% of children experience relapse within 5 years 3
- The goal is 1 non-forced bowel movement every 1-2 days 7
- Do not discontinue treatment prematurely—functional constipation requires prolonged maintenance to prevent relapse 2, 3
Critical Pitfalls to Avoid
Age-Inappropriate Medications
- Never use stimulant laxatives (bisacodyl, senna) in toddlers—these are only appropriate for older children and dying patients in palliative care 7, 8
- Avoid magnesium-based laxatives in young children 7
Inadequate Dosing and Duration
- The most common treatment failure is using insufficient doses for too short a duration 6
- Treatment often requires months to years, not weeks 2
Missing Organic Causes
- While 95% of constipation is functional, watch for red flags: failure to pass meconium in first 48 hours of life, ribbon stools, blood in stools without anal fissures, severe abdominal distension, abnormal neurological examination, or failure to thrive 2, 3
Adjunctive Measures
Dietary Modifications
- Dietary fiber shows no significant benefit over placebo in increasing defecation frequency (only 0.35 additional bowel movements per week) 1
- Consider a trial of withholding cow's milk, as it may promote constipation in some children 2
- Ensure adequate fluid intake 7