Baby poo colours: what is normal and when to call the doctor

Most of what you'll see in your baby's nappy is normal. The first poo, meconium, is sticky and greenish-black. After a few days it turns yellow or mustard. Breastfed poo is runny, formula poo is firmer and smellier, and green, yellow, tan and brown are all usual shades.

A few colours need a doctor the same day: white, pale grey or pale creamy poo, red blood, and black poo once the meconium days are over. This guide walks through each stage, how often babies poo, and when a change needs help.

What should my newborn's poo look like in the first week?

The NHS describes the first poo, meconium, as sticky and greenish-black. It may come during or after birth, or some time in the first 48 hours. The AAP calls it black and tarry looking, and expected. After a few days, poo changes to a yellow or mustard colour.

A Norfolk NHS community health service publishes this day-by-day guide for breastfed babies:

The NHS breastfeeding guidance says breastfed babies aged 4 days to 6 weeks should pass at least 2 yellow poos a day. If there's been no poo for 24 to 48 hours, speak to your midwife or child-health nurse, as it can mean your baby isn't getting enough milk. The Norfolk service also says to tell your midwife or health visitor if there are fewer nappies than the table shows.

If your baby hasn't passed meconium within 48 hours of birth, Pregnancy, Birth and Baby advises seeing a doctor.

What does normal breastfed and formula-fed poo look like?

The NHS describes breastfed poo as runny with no smell, and formula poo as firmer, darker brown and smellier. The AAP calls mustardy yellow the usual breastfed colour and yellow-tan with hints of green the usual formula colour. The NHS adds that some formulas can turn poo dark green.

The AAP considers all the shades of yellow, brown and green that follow meconium acceptable. The colours to act on are white or pale, red and black.

How often should a baby poo?

The range of normal is wide, and it changes with age and feeding:

• First week: The NHS says babies do 2 or more poos a day in the first week.
• Breastfed babies: They may poo at every feed in the early weeks. After about 6 weeks, some go several days without one. Pregnancy, Birth and Baby says some breastfed newborns poo up to 7 times a day, while others poo only once every 7 to 10 days.
• Formula-fed babies: The NHS says they may poo up to 5 times a day as newborns, often dropping to about once a day after a few months. Pregnancy, Birth and Baby says formula-fed babies usually poo every 1 to 2 days.
• By 1 year: The NHS gives an average of 2 a day.

The NHS says a baby isn't constipated if their poos are soft, even after a few days without one. Straining, going red and crying before a soft poo is also common. Pregnancy, Birth and Baby says healthy babies under 9 months often do this, and it isn't constipation unless the poo is hard. See constipation for hard poos.

How does poo change when my baby starts solids?

The AAP's starting solids page says poo becomes more solid and variable in colour, with a much stronger smell. Peas and other green vegetables can turn it deep green, and beetroot can make it red. Pieces of undigested food, such as pea or corn skins, are normal.

If poo becomes extremely loose, watery or full of mucus, the AAP suggests cutting back on solids, introducing them more slowly, and talking to your doctor if it continues. Our starting solids guide covers first foods.

Which poo colours mean I should call the doctor?

The Royal Children's Hospital Melbourne (RCH) also says to take your child to a doctor if their poo is white, red or black.

White or pale poo

The AAP says white poo is rare but needs a doctor's attention as soon as possible, because it can come from a liver problem. One cause is biliary atresia, where the bile ducts are blocked. AAP HealthyChildren says it's rare, and affected babies usually look healthy at birth. Jaundice and pale poo typically develop by 4 to 6 weeks of age.

Liver UK says the operation used to treat it is best done in the first 2 to 3 months of life. The NHS jaundice page asks for an urgent GP or midwife appointment if a baby's poo is pale or their wee is dark yellow or brown. Ask to be seen the same day, and take a photo or the nappy with you.

Black poo

Black poo in the first few days is meconium. The AAP explains that blood darkens to black as it moves through the gut, so black poo after the meconium stage is worth checking. The Norfolk NHS service advises a GP check for black poo after the first 5 days.

Red streaks or blood

The AAP says any amount of blood in a baby's poo should be checked, though it isn't a reason to panic. The NHS reflux page lists blood in poo as a reason for an urgent GP appointment. Remember that beetroot can make poo red once solids start. If there's more than a streak of blood, or your baby is vomiting, has a swollen tummy, is pale or floppy, or seems unwell, call your local emergency number (000 in Australia, 999 in the UK, 911 in the US).

Jaundice after 2 weeks

The NHS says newborn jaundice usually takes around 2 weeks to go. If your baby still looks yellow after that, call your GP or child-health nurse today to arrange a check. If the poo is pale or the wee is dark, ask to be seen today. See newborn jaundice.

Is it diarrhoea, and when is it dangerous?

Breastfed poo is naturally runny, so what matters is a change. The NHS says to talk to your doctor if poo becomes very watery, very smelly or harder than usual, particularly if there's blood in it.

The RCH gastroenteritis fact sheet says babies under 6 months are at higher risk of dehydration. It advises:

• Keep breastfeeding, and feed more often.
• See a doctor if a baby under 6 months is vomiting or has a fever with gastro.
• See a doctor for 8 to 10 watery poos a day, blood in the poo, or diarrhoea lasting more than 10 days.
• Go to hospital if your child can't keep fluids down and has several signs of dehydration.
• Call your local emergency number (000 in Australia, 999 in the UK, 911 in the US) if your child is very lethargic or hard to wake.
• Don't give over-the-counter medicines that reduce vomiting or diarrhoea, as they may be harmful for children.

The RCH dehydration fact sheet says any baby under 6 months with signs of dehydration should see a doctor. Signs include fewer wet nappies, darker wee and a dry mouth. See dehydration signs.

When should I get help for a poo problem?

These tiers match our when to call the doctor guide.

Call your local emergency number (000 in Australia, 999 in the UK, 911 in the US) now if:

• There's more than a streak of blood, or black tarry poo, and your baby is vomiting, has a swollen tummy, or is pale, floppy or unwell.
• Your baby has green or yellow vomit.
• Your baby is very sleepy and hard to wake, or has had no wet nappy for 12 hours.
• Your baby is under 3 months and has a temperature of 38°C or more.

Get medical help today if:

• Poo is white, pale grey or pale creamy, or wee is dark in a jaundiced baby.
• There's blood in the poo, or black poo after the meconium days.
• A baby under 6 months has diarrhoea with vomiting or fever, or any sign of dehydration.
• A newborn has had no poo for 24 to 48 hours in the first 6 weeks.

Talk to your GP or child-health nurse if:

• Poos are hard, dry or pellet-like, or your baby seems to be in pain passing them.
• Green poo comes with feeding worries or slow weight gain.
• Loose or mucus-filled poos keep happening after starting solids.

What is worth noting about your baby's poo?

A short note of the time, colour, texture and amount, plus wet nappies, helps you spot a change from your baby's usual pattern. A clear photo of an unusual nappy is often more useful to a doctor or nurse than a description. If you notice a red-flag colour, get help first and write things down later.