MiraLAX Dosing for a 2-Year-Old
For a 2-year-old child (12-14 kg), start with 0.8 g/kg/day of polyethylene glycol 3350 (MiraLAX), which translates to approximately 10-11 grams daily (roughly 2 leveled teaspoons or 1 leveled tablespoon), mixed in 4-8 ounces of liquid, given once daily.
Dosing Algorithm
Initial Dose
- Weight-based calculation: 0.8-1.0 g/kg/day is the evidence-based starting point for children under 2 years 12
- For a 12 kg child: ~10 grams daily
- For a 14 kg child: ~11 grams daily
Practical Measurement
Since the standard adult capful is 17 grams 3, this is too much for a toddler. Instead:
- Use 2 leveled teaspoons (approximately 6.6 grams) to 3 leveled teaspoons (approximately 10 grams) 4
- Or use 1 leveled tablespoon (approximately 10 grams) 4
- Leveling the measuring device is critical to avoid dose variability 4
Dose Titration
- Goal: Achieve 1-2 soft, painless stools per day 1
- Adjust dose every 3 days based on response 5
- Effective maintenance range: 0.78-1.1 g/kg/day in children under 24 months 12
- If diarrhea occurs, reduce the dose immediately—this is the most common side effect and resolves with dose adjustment 1
Evidence Supporting This Recommendation
The most relevant pediatric studies specifically examined children under 2 years of age. A retrospective review of 75 infants and toddlers found that mean effective short-term dose was 1.1 g/kg/day and long-term maintenance was 0.8 g/kg/day, with 85% short-term and 91% long-term success rates 1. Another study of 28 children under 18 months demonstrated 97.6% efficacy with a mean maintenance dose of 0.78 g/kg/day 2.
Safety Profile
PEG 3350 is safe and well-tolerated in this age group 612:
- Adverse effects are mild and transient
- Most common: diarrhea (resolves with dose reduction) and transient abdominal discomfort
- No clinically significant electrolyte abnormalities reported
- No subjects discontinued therapy due to adverse effects in the key studies 12
Important Clinical Considerations
Administration Tips
- Mix the powder completely in any beverage—it's unflavored and grit-free 3
- Ensure adequate fluid intake throughout the day
- Can be given at any time of day, but consistency helps with adherence
Common Pitfalls to Avoid
- Don't use the adult capful (17g) as the measuring device for toddlers—this overdoses them
- Don't use "heaping" measurements—these create significant dose variability (up to 15 grams per tablespoon) 4
- Don't stop too early—studies show sustained efficacy over 6-11 months of treatment 1
- Don't ignore diarrhea—immediately reduce dose if loose stools develop
When to Adjust
- Increase dose if: fewer than 3 bowel movements per week, continued straining, or hard stools persist after 3 days
- Decrease dose if: diarrhea, more than 3 stools daily, or watery consistency
- Maximum tested dose: Up to 1.26 g/kg/day has been used safely, though most children respond to lower doses 1
Duration of Therapy
Long-term use is appropriate and safe. The mean duration in pediatric studies was 6-11 months, with some children treated for up to 21 months without adverse effects 12. Adult guidelines support PEG use for at least 6 months 7, and this translates to pediatric practice.