White, Pale or Black Baby Poop: Colours That Need Medical Attention

A clean diaper on a wooden table next to mustard, brown, white and black colour cards, a hand touching the brown one

Most baby poop colours are fine. Two aren't. Pale poop, meaning white, grey, chalky or clay, needs a doctor today. Black poop does too, once the first few days are over. Both are rare, and both are easy to miss at 3am under a yellow lamp.

Black in the first days is normal

The first poops are meconium. Black or very dark green, thick and sticky. It's what built up in the gut before birth. NHS Grampian's midwives say a baby passes it maybe three or four times. Then it shifts through brown and green to yellow, and gets looser around day four. Black on day one is expected. Black at two weeks isn't.

Dark green that looks black

Iron does this. Iron-fortified formula and iron drops can turn poop dark green, and Seattle Children's lists iron as a cause of both green and black stools. It also says dark green can look black in poor light. That's the light you'll be changing diapers in for months. Look again by a window in daylight before you worry. If your baby's on iron and you're unsure, don't stop the drops without asking your doctor first.

Black and tarry is different

Tarry poop is black, sticky and shiny, like road tar. MedlinePlus, the US National Library of Medicine's health site, says it usually means bleeding high in the gut, because stomach acid turns blood dark. One harmless cause gets mentioned a lot. A breastfed baby can swallow blood from a cracked nipple, and it comes out dark. An emergency medicine teaching page says that's rarer in practice than the textbooks suggest. A doctor can test the poop to see whose blood is in it. You can't tell from the diaper, so call the same day and let them test it.

Pale, grey, white or clay

This is the one I'd want every parent to know. Bile is what makes baby poop yellow and green. If bile can't get from the liver to the gut, the poop goes pale: pale yellow, grey, chalky white, the colour of putty. Seattle Children's says babies with blocked bile ducts pass light grey or pale yellow stools. The rare cause doctors worry about is biliary atresia, where the bile ducts outside the liver are blocked or missing. A 2015 study put it at about 1 in 13,000 births in the US, and Taiwan's screening found close to 4 in 10,000. Without surgery it's fatal. The operation is called a Kasai, and the same study says the best outcomes come when it's done within 60 days of birth.

Weeks count. Pale poop often comes with two other signs. One is wee that's dark yellow, when a newborn's should be nearly colourless. The other is jaundice, yellow skin or eyes, that hangs on past two weeks, or three weeks for a baby born early. On darker skin, the Children's Liver Disease Foundation suggests checking the whites of the eyes, the gums, the palms and the soles.

Sometimes the poop just looks a bit light and it's nothing. Not sure? Get it checked anyway.

The everyday colours

How Taiwan and Japan catch it early

Both hand parents a stool colour card. It's a strip of photos, normal shades and pale ones, kept with the child health booklet. In Taiwan's pilot in 2002 and 2003, the card flagged 26 of the 29 babies later found to have biliary atresia before they were 60 days old. Japan's Tochigi prefecture ran a card for 19 years across 313,230 babies. It caught about three in four cases, and the Kasai was done at about 60 days on average.

I couldn't find a card like that given to parents in Singapore. In the UK the Children's Liver Disease Foundation makes one for health workers. Until someone hands you one, look at the diaper in daylight for the first month and know the pale shades.

Photos get colour wrong

Take a photo anyway, but don't trust it. A phone picture under a warm bedside lamp isn't the colour of what's in the diaper. In the 2015 study behind a stool colour app, the authors noted that doctors themselves often can't tell pale stools from normal ones by eye. A doctor has a blood test for this. Give them what they need to decide to use it.

The diaper itself. NHS advice for a jaundiced baby with pale poop is to keep a sample to show the midwife or doctor. Fold it, bag it, bring it.
Photos in daylight, by a window, no flash, with something white beside the diaper.
Photos from several days if the colour has been changing.
A note of feeds, wet diapers, and any iron drops or medicines.
Whether the skin or eyes look yellow, and since when.

Our third had dark green poop for months on iron drops. I photographed it under the kitchen light. It looked black in the photo and dark green by the window the next morning, which is what it had been all along.

Then stop searching and let the doctor look, because a blood test can answer in a day what a page like this one can't.

Questions I get asked

Is white or pale baby poop an emergency?

It needs a same-day call to a doctor. Pale, grey, white or clay-coloured poop can mean bile isn't reaching the gut. Biliary atresia, the rare cause doctors check for, is best treated within about 60 days of birth.

Is black poop normal in a newborn?

In the first few days, yes: that's meconium. Black or tarry poop after the first week needs a call the same day, unless your baby takes iron and it's very dark green in daylight.

Can iron drops turn baby poop black?

Iron can turn poop dark green, and dark green can look black in poor light. Don't stop iron without asking your doctor, and call if the poop is tarry or your baby seems unwell.

Should I photograph my baby's poop for the doctor?

Yes, in daylight without flash, but keep the diaper too. Photos shift colour, and NHS advice for a jaundiced baby is to bring a sample.

Where the numbers come from

This guide is general information, written to help you understand a topic and ask better questions. It is not medical advice and does not replace your own doctor, midwife or paediatrician. Anything that worries you about your baby belongs with them.

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