Foamy Frothy Baby Poo: Foremilk-Hindmilk Balance | Parenting Hub
Green, foamy, frothy poo in a breastfed baby is usually about how — not how much — milk is flowing. Here's how to fix it.
Foamy or frothy, often-green poo in a thriving breastfed baby is usually a feeding-pattern thing, not an illness. A small tweak often fixes it.
Why poo goes frothy
When a breastfed baby takes a lot of the watery, lactose-rich early milk (foremilk) and not as much of the fattier later milk (hindmilk), the gut moves things through quickly. Extra lactose ferments and produces bubbles — hence frothy, often-green poo.
What to try
- Finish the first breast before offering the second — let baby come off on their own
- Try 'block feeding': same breast for 2–3 hours, then swap
- If you have a strong let-down or oversupply, see our oversupply article
- Watch for milk dribbling from the corner of baby's mouth (a sign of fast flow)
What this is NOT
Not lactose intolerance — true infant lactose intolerance is rare. Not an allergy unless there's blood/mucus, eczema or poor weight gain (see CMPA article).
When to seek help
- Blood or persistent mucus in the poo
- Poor weight gain
- Severe eczema, vomiting, hives — see CMPA
- Watery diarrhoea + dehydration signs
Common questions
Do I need a lactose-free formula?
Almost never. Try the feeding adjustments first and see an IBCLC if you're unsure. Don't switch formulas without guidance.