What is the recommended management for a 6‑month‑old infant who becomes upset after a bowel movement?

Management of a 6-Month-Old Becoming Upset After Pooping

The most likely explanation is painful defecation from constipation, and treatment should begin immediately with polyethylene glycol (PEG) as first-line therapy, as lactulose/lactitol are the only alternatives authorized for infants under 6 months but PEG is preferred for those 6 months and older. 1, 2

Clinical Assessment

Determine whether the infant has functional constipation by looking for:

• Infrequent bowel movements (≤2 per week) 3
• Hard, painful stools that cause the infant to scream or cry during defecation 4
• Stool-holding behaviors (arching back, stiffening legs, clenching buttocks) 4
• Large-diameter stools 3

Examine the stool consistency using the Bristol stool chart as a monitoring tool for parents 3. Visual inspection should confirm hard consistency 5.

Red Flags to Rule Out Organic Causes

Before diagnosing functional constipation, actively exclude:

• Delayed passage of meconium beyond 48 hours of life (suggests Hirschsprung's disease) 3
• Abdominal distension or signs of intestinal obstruction 5
• Developmental delays or neurologic abnormalities 3
• Poor weight gain or failure to thrive 2

Hirschsprung's disease occurs in 1 in 5,000 births and presents with severe constipation from birth 4. If suspected based on history or examination, refer immediately for rectal biopsy 4.

Treatment Protocol

Step 1: Assess for Fecal Impaction

If a large fecal mass is palpable on abdominal examination or if there is overflow incontinence (liquid stool leaking around hard stool), disimpaction is required first 1, 2:

• High-dose PEG for 3-6 days (escalate dose until disimpaction achieved) 1
• Alternatively, phosphate enemas can be used, though less preferred in infants 1

Step 2: Maintenance Laxative Therapy

For a 6-month-old, polyethylene glycol (PEG) is the preferred first-line maintenance therapy 1, 2:

• PEG is authorized and effective for infants over 6 months of age 1
• Lactulose or lactitol are alternatives authorized before 6 months but can be continued if already started 1
• Dosing for lactulose in infants: 2.5-10 mL daily in divided doses 6
• The goal is to produce 2-3 soft stools daily 6, 1

Critical dosing principle: Use a sufficient dose for a prolonged duration (months to years may be required) 1, 4. If diarrhea develops, reduce the dose immediately 6.

Step 3: Dietary and Behavioral Modifications

• Continue age-appropriate feeding without restriction 5
• For formula-fed infants, maintain full-strength formula 5
• For breastfed infants, continue breastfeeding on demand 7
• Avoid relying solely on dietary interventions (water, juice, or fiber) as treatment for established constipation 1

Step 4: Establish Regular Bowel Habits

Once the infant is older and can sit independently:

• Encourage daily attempts at defecation after meals (to utilize gastrocolic reflex) 1
• Ensure proper positioning with feet supported 1

Common Pitfalls to Avoid

• Do not delay treatment while waiting for spontaneous resolution—constipation creates a vicious cycle of painful defecation leading to stool withholding, which worsens the problem 3
• Do not use inadequate doses or discontinue therapy too early—this is the most common cause of treatment failure 1, 4
• Do not rely on dietary changes alone (mineral water, increased fluids, or fiber) as primary treatment for established constipation 1
• Do not use mineral oil, suppositories, or enemas as first-line therapy in infants 1

When to Reassess or Refer

Return for reassessment if:

• No improvement after 2-4 weeks of appropriate-dose laxative therapy 2
• Persistent severe symptoms despite treatment 2
• Any red flags develop (abdominal distension, vomiting, developmental concerns) 3, 8

Reassure parents that functional constipation is common, not life-threatening, but requires consistent treatment over months to prevent relapse 1, 4.