What laxatives are safe for babies with constipation?

Laxatives for Babies with Constipation

For infants under 6 months, lactulose or lactitol are the authorized and effective first-line laxatives; for babies 6 months and older, polyethylene glycol (PEG) is the preferred first-line treatment due to superior efficacy and safety. 1, 2

Age-Specific Laxative Recommendations

Infants Under 6 Months

• Lactulose is the primary treatment option, with an initial dose of 2.5-10 mL daily in divided doses 3, 1
• Lactitol-based medications are equally authorized and effective in this age group 1
• If diarrhea develops, reduce the dose immediately; if diarrhea persists, discontinue the medication 3
• The goal is to produce 2-3 soft stools daily 3

Infants 6 Months and Older

• Polyethylene glycol (PEG 3350) is the most effective laxative, achieving significantly more treatment success than all other laxatives (47% better success rate) 4, 5
• PEG demonstrates excellent efficacy, safety, and patient acceptance for both short-term and long-term treatment 2, 5
• Lactulose remains an alternative option with doses of 40-90 mL daily for older children and adolescents, though it is less effective than PEG 3, 4

What Does NOT Work in Babies

• Dietary fiber and hyperosmotic mineral water are not effective treatments for established constipation at any age 1
• Bulk-forming laxatives like psyllium should be avoided 6
• Simple dietary modifications alone are insufficient once constipation is established 1

Managing Fecal Impaction in Babies

If fecal impaction is present (identified by digital rectal examination showing a hard stool mass):

• First-line treatment is glycerine suppository with or without mineral oil retention enema 7
• Alternatively, use high-dose PEG for the first few days or repeated phosphate enemas 1
• Never give oral laxatives alone without addressing the physical impaction first—the mass must be mechanically disrupted 7
• After disimpaction, immediately start maintenance therapy with PEG to prevent recurrence 7, 1

Critical Safety Considerations

Magnesium-Based Laxatives

• Magnesium salts (magnesium hydroxide, magnesium citrate, magnesium sulfate) should be avoided in babies due to risk of hypermagnesemia, especially with any degree of renal impairment 6, 8
• These agents can accumulate and cause serious cardiac and neurologic toxicity 8

Stimulant Laxatives

• Stimulant laxatives (senna, bisacodyl) are generally not first-line in infants but may be used as adjunct therapy in specific clinical scenarios 2
• They are among the safest drugs when used appropriately, despite common misconceptions 9

Enema Contraindications

• Never use enemas in babies with neutropenia, thrombocytopenia, recent abdominal surgery, rectal trauma, or undiagnosed abdominal pain 6, 7
• Avoid soap suds or alkaline enemas 3

Treatment Duration and Dosing Principles

• The rule for treatment is sufficient dose for a long time—underdosing and premature discontinuation are common pitfalls 1
• Treatment should continue until normal bowel patterns are established and maintained 1
• Adjust doses based on response: the goal is 2-3 soft stools daily, not diarrhea 3, 1

Common Pitfalls to Avoid

• Delaying treatment leads to psychosocial and digestive consequences 1
• Using insufficient doses or stopping treatment too early results in relapse 1
• Attempting to treat impaction with oral laxatives alone without mechanical disimpaction 7
• Prescribing fiber supplements or dietary changes as primary therapy for established constipation 1