Treatment of Constipation in an 8-Year-Old Male
Start with polyethylene glycol (PEG) 17 grams once daily mixed in 4-8 ounces of beverage as first-line pharmacologic therapy, combined with increased fluid intake and dietary modifications. 1
Initial Assessment and Disimpaction
Before starting maintenance therapy, perform a digital rectal examination to rule out fecal impaction 2. If impaction is present:
- Administer 1-2 phosphate enemas to achieve disimpaction 3
- Do not proceed with maintenance therapy until the rectum is cleared 3
First-Line Maintenance Treatment
Polyethylene Glycol (PEG)
- Dosing: 17 grams (one capful or packet) dissolved in 4-8 ounces of any beverage once daily 1
- Ensure powder is fully dissolved before drinking; do not drink if clumps remain 1
- Can be given in cold, hot, or room temperature beverages 1
- Do not combine with starch-based thickeners 1
- PEG is safe for use beyond 7 days in children, despite over-the-counter labeling 1
Supportive Dietary Measures
- Increase fluid intake, particularly if the child is in the lowest quartile of daily fluid consumption 4
- Fiber supplementation can be added if the child has adequate fluid intake 4
Behavioral Modifications
- Have the child sit on the toilet 4 times daily after meals to utilize the gastrocolic reflex 3
- Encourage regular physical activity when appropriate 4
Treatment Goal
Achieve one non-forced bowel movement every 1-2 days without abdominal pain or straining 4
Second-Line Options if PEG Fails
If constipation persists after 4 weeks of PEG therapy:
Add Stimulant Laxatives
- Bisacodyl: 5-10 mg once daily (pediatric dosing, lower than adult 10-15 mg) 4
- Administer 30 minutes after a meal to synergize with gastrocolic response 4
Alternative Osmotic Agents
- Lactulose: 1-2 mL/kg/day divided twice daily 4
- Magnesium hydroxide (Milk of Magnesia): age-appropriate dosing 4
- Sorbitol: can be used as alternative osmotic agent 4
Management of Persistent Constipation
Reassess for Underlying Causes
- Rule out medication-induced constipation and discontinue non-essential constipating drugs 4
- Check for overflow diarrhea suggesting impaction 4
- Consider metabolic causes only if other symptoms present (hypercalcemia, hypokalemia, hypothyroidism, diabetes) 4
Rescue Interventions for Impaction
- Glycerin suppository for mild impaction 4
- Bisacodyl suppository (5-10 mg rectally) for moderate impaction 4
- Mineral oil retention enema for severe cases 4
- Manual disimpaction with pre-medication (analgesic ± anxiolytic) if necessary 4
Important Clinical Considerations
Evidence Quality
The recommendation for PEG is based on moderate-quality evidence in adults 4, with supportive pediatric data showing glucomannan fiber supplementation benefits 45% of children versus 13% with placebo 3. Children with constipation alone (without encopresis) respond better to fiber (69% success) than those with both conditions (28% success) 3.
Common Pitfalls to Avoid
- Do not use stool softeners alone (docusate): Evidence shows senna alone is equally or more effective than senna-docusate combinations 4
- Do not add supplemental fiber without adequate fluid intake: This can worsen constipation 4
- Do not use wheat bran as finely ground powder: It can decrease stool water content and harden stool 4
- Do not limit PEG to 7 days in chronic constipation: The over-the-counter labeling is conservative; PEG has demonstrated safety and efficacy for 6 months 4, 1
Duration of Treatment
Most children require several months of treatment, as the average duration of constipation before presentation is 4 years 3. Response to fiber supplementation is independent of initial fiber intake adequacy or duration of constipation 3.