Newborn's first poos: meconium and the transition to milk stools

What's probably happening

Newborn stools change predictably across the first 5–7 days as feeding gets going.

• Days 1–2: meconium. Sticky, tar-like, black or very dark green. Hard to wipe off. This is the bowel clearing what built up in utero.
• Days 3–4: transition stools. Looser, lighter, greenish-brown or army green. Feeding is moving things through.
• Day 5 onward (breastfed): yellow, seedy, loose. Mustard colour, often with small curd-like bits. Can be runny enough to look like diarrhoea. That's normal.
• Day 5 onward (formula-fed): tan or pale brown, thicker. More paste-like, less frequent than breastfed stools.

Expected counts in the first week: at least one dirty nappy on day 1, two by day 2, three by day 3, and from day 5 around 3–4 dirty nappies and 6+ heavy wet nappies in 24 hours.

When to escalate

See a doctor when you can:

• No transition off meconium by day 4.
• Pale, white, chalky, or putty-coloured stools at any age. This needs review for liver or bile-duct problems.

Get immediate medical care:

• No stool at all in the first 24 hours of life.
• No stool by day 4 in a breastfed baby, or by day 2 in a formula-fed baby.
• Blood in the stool — streaks, spots, or mixed through.
• Black tarry stool after day 4 (after meconium has cleared).
• Fewer than 5 heavy wet nappies in 24 hours after day 5.
• Fever > 38°C in a baby under 3 months.