Lactulose in Pregnancy: Safety, Dosing & Side Effects

Lactulose is an osmotic laxative (non-absorbable disaccharide) FDA Category B in pregnancy—considered safe.

Mechanism

Draws water into colon → softens stool, stimulates peristalsis. Fermented by colonic bacteria → SCFAs, gas.

Dosing & Tips

• Start low: 15 ml daily; titrate to 2–3 soft stools/day.
• Take with full glass water.
• Split dose (BID) reduces bloating.
• Onset: 24–48 hours.

Side Effects

• Gas, bloating, cramping (common initially)
• Nausea, diarrhea (if overdosed)
• Electrolyte imbalance (rare with appropriate use)

Contraindications/Precautions

• Bowel obstruction, perforation, galactosemia.
• Use caution with severe abdominal pain of unknown cause.

No evidence of fetal harm. Always inform OB/GYN. First-line for pregnancy constipation after fiber/fluids fail.