Newborn poo differs from an adult’s or even an older baby’s poo in some very distinct ways. You will notice it change quickly in the first few days following birth once your baby’s digestion gets up and running.

Your newborn’s first poo: meconium

Your baby’s first poo will be unmistakable in appearance. This type of poo is called meconium and closely resembles motor oil in its browny-black colour, texture and stickiness. Meconium is made up of amniotic fluid, dead cells, bile and mucus – the leftovers from your baby’s time in the womb.

Meconium has almost no odour, so you might have to regularly check on your baby to see whether they need a nappy change.


If you are breastfeeding, your milk will act as a laxative to push all that meconium out of your baby’s digestive tract. This will also result in a change to your baby’s poo colour, odour and texture.

Poo from breastfeeding tends to be sweeter in smell and has a greeny-yellow colour, like army fatigues or mustard. Its consistency is mushy to liquid and it often has a granular texture. You might notice it change slightly, especially in colour, depending on your diet.

Formula feeding

The poo produced by formula tends to be thicker in consistency and more brown and yellow than green. It retains some of that granular texture produced by babies who are breast-fed, however the odour is more pungent than sweet.


Constipation in a newborn can occur in both breast-fed and formula-fed babies. In the former it might be because of an intolerance to something in your diet, while the latter might be an intolerance to something present in the formula. Your baby will have trouble passing the more solid poo produced by constipation, and it may be tinged with blood. If constipation continues for more than a couple of days, it’s best to see a medical professional to find out why.

Note: your baby’s poos will become naturally firmer and more formed once they start the switch to solids.


Poo from diarrhoea will appear more liquid than solid, and can be a range of colours from yellow, to green to brown. While one or two incidences of diarrhoea over a day might not indicate anything serious, any more is cause for concern – particularly in babies under 3 months old. To avoid further dehydration and nutrition loss, it’s best to take your baby to a doctor or paediatrician to discover the cause.

Things to look out for

  • It’s not uncommon for babies to poo immediately after – and sometimes during – a feeding session.
  • If you are breastfeeding and your baby’s poo turns green and frothy, it is likely that they haven’t had enough of the more nutritious milk held deeper in your breasts. You can reach these reserves by starting your next feed on the breast your baby previously finished feeding on.
  • Although blood with more solid poos is a sign of constipation, in runnier poos it can be a sign of allergy or bacterial infection.
  • Poo that seems coated in mucus or slime is usually a result of excessive saliva ingestion. But if it continues for more than two days, it could be best to speak to a doctor.
With your baby’s health so precarious at this stage of life, anything that falls drastically outside the spectrum – including red, white or black poo – should be responded to with immediate medical attention.