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Baby poop: what is normal, and the colors that matter
Last verified: July 9, 2026
The short answer
- The first poo is sticky and greenish black, then it turns yellow or mustard
- Breastfed and formula-fed poo look different, and both are fine
- Frequency varies wildly, from several a day to several days apart
- Three colors matter: pale or chalky, red, and black after the early days
Few things get inspected as closely as the contents of a nappy. The good news is that a very wide range is normal. This guide covers what to expect, and the small number of things worth a call.
The first poo: meconium
Your baby’s first poo is called meconium. It is sticky and greenish black, almost like tar, and it can appear during or shortly after birth, or any time in the first 48 hours (NHS: How to change your baby’s nappy). It looks alarming and is completely normal. After a few days, as feeding gets going, it changes to a yellow or mustard color.
Breast, formula, and the colors in between
What goes in shapes what comes out.
Breastfed babies tend to have runny poo that does not really smell, often yellow or mustard. Formula-fed babies have firmer poo that is darker brown and smellier. Some formulas can turn poo dark green, which is not a problem. And if you switch from breast to formula, expect the poo to get darker and more paste-like. None of this means anything is wrong.
How often is normal
The honest answer is that the range is enormous. In the first week, babies do 2 or more poos a day. By their first birthday, that settles to around 2 a day on average.
Within that, the patterns differ by feeding. A breastfed newborn may poo at nearly every feed in the early weeks, and then, after about 6 weeks, go several days without one. A formula-fed newborn may poo up to 5 times a day, dropping to around once a day after a few months.
One thing that worries many parents needlessly: it is normal for a baby to strain, go red, or even cry while doing a poo. That alone is not constipation. The test is simple. As long as the poo is soft when it arrives, your baby is not constipated, even if a few days have passed.
Normal changes, and the ones that are not
From day to day and week to week, your baby’s poo will vary in color and texture. That drift is expected.
What is worth a mention to a professional is a definite change: poo that becomes very smelly, very watery, or much harder, especially if there is any blood in it. The NHS says talk to your doctor or health visitor if you notice this.
Two girls’ notes while we are here. In the first few days, a baby girl may have a little white discharge in the nappy, and occasionally slight bleeding like a mini period. Both are caused by your hormones crossing over before birth, and both pass on their own.
The colors that matter
Most poo colors are just diet. Three are worth acting on.
- pale, chalky or creamy-colored poo, which can be a sign of jaundice
- poo that suddenly turns very smelly, very watery, or much harder than usual
- any streak of blood in the poo
Pale poo deserves its own line. Alongside dark yellow or brown pee, the NHS treats pale, creamy poo in a baby over 24 hours old as a reason to ask for an urgent GP or midwife appointment, or call 111, because it can point to jaundice that needs checking (NHS: Jaundice in babies). If you can, keep the nappy to show them. Our newborn jaundice guide explains the whole picture, from the normal day-3 yellow to the signs that need help.
- a baby with jaundice who is sleepy and hard to wake, floppy, or not feeding
- blood in the poo together with a swollen tummy, forceful vomiting, or a distressed baby
- a high temperature of 38C or more in a baby under 3 months
Keep reading
- Baby reflux and spitting up
- Nappy rash: what helps, and when to call
- Starting solid food: the real rules
- Baby fever: when to worry
- All the first-year windows
Sources
- NHS: How to change your baby’s nappy (page last reviewed August 2024)
- NHS: Jaundice in babies (page last reviewed March 2026)
- NHS: Is your baby or toddler seriously ill? (page last reviewed August 2023)
Peanutbean provides general information for educational purposes only. It is not medical advice. Every baby develops at their own pace. Always talk to your pediatrician about your child’s health.
Common questions
What color should my baby's poop be?
The first poo, meconium, is sticky and greenish black. After a few days it turns yellow or mustard. Breastfed poo is runny and barely smells; formula poo is firmer, darker brown and smellier. Some formula can make it dark green. The colors that need a doctor are pale or chalky, red with blood, or black after the first days.
How often should a baby poop, and is mine constipated?
It varies hugely. Newborns often go several times a day, and a breastfed baby over 6 weeks can go several days without a poo. Straining or even crying while pooing is normal. Your baby is not constipated as long as the poo, when it comes, is soft.
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