Newborn stool changes colour and frequency several times in the first weeks, and most of that change is normal — not a sign that something is wrong with the feed. What matters is a small set of specific colours (white, black after the first few days, or red) and a pattern of no stool at all for several days, both of which are worth a call to your paediatrician.

What's normal, feed by feed

  • The first 2–3 days — dark, sticky, tar-like stool (meconium), regardless of what your baby is fed
  • Days 3–5 — a transitional greenish-brown or greenish-yellow stool as feeding gets established
  • Exclusively formula-fed — pale yellow, tan, or light brown, usually firmer and more formed than breastfed stool, typically once a day to a few times a day
  • Combination-fed (breast + formula) — a mix of the two patterns; often looser and more mustard-yellow after a breastfeed, firmer and tan-brown after a formula feed — this back-and-forth is expected, not a sign of intolerance
  • Frequency on formula or combination feeds — anywhere from several times a day down to once every 1–2 days can be normal, as long as the stool is soft and your baby isn't uncomfortable

Colours that are still usually fine

Greenish stool is one of the most common things that worries parents but is rarely a problem on its own — it can happen with a faster gut transit, a change in formula brand, or simply how that feed digested. Grey-green or olive tones fall in the same normal range. If your baby is feeding well, gaining weight, and comfortable, colour alone in this range isn't a reason to change anything.

Colours and patterns that need a call to the doctor

  • White or pale, chalky stool — can indicate a liver or bile-drainage problem and needs same-day evaluation
  • Black stool after the first few days (once meconium has passed) — can mean digested blood
  • Red stool, or visible blood or mucus — needs to be checked, even if your baby otherwise seems well
  • No stool for more than 5–7 days combined with a hard, firm abdomen, discomfort, or refusal to feed — occasional gaps of a few days can be normal on formula, but this combination is not

A wide range of yellow, tan, brown, and green is normal on formula or combination feeds. It's the white, black (after the newborn period), or red stool — not the everyday shade of yellow or green — that's the actual signal to act on.

Frequently asked

Is it normal for my formula-fed baby to skip a day without pooping?

Yes, occasionally — formula-fed babies tend to have firmer, less frequent stool than exclusively breastfed babies, and going a day or two without one can be normal as long as the stool is soft when it comes and your baby isn't straining or uncomfortable. A longer gap paired with a hard abdomen or visible discomfort is when it's worth a call.

Does switching formula brands change stool colour?

It can — a new formula can shift the stool towards a different shade of tan, brown, or green for a few days as your baby's gut adjusts. This alone isn't a cause for concern unless it comes with white, black, or red stool, or signs of discomfort.

Why does my combination-fed baby's stool look different after each type of feed?

Breast milk and formula digest differently, so it's common for stool to be looser and more yellow-green after a breastfeed and firmer and more tan-brown after a formula feed. Seeing both patterns in the same day is expected on a combination-feeding routine, not a sign either feed disagrees with your baby.

What should I do if I'm not sure whether a colour is normal?

A photo is genuinely useful here — most paediatricians are happy to look at a picture over a call or message rather than have you guess. When in doubt, especially with any hint of white, black, or red, it's always reasonable to get it checked rather than wait.