What is meconium and when should a newborn pass it?
Meconium is a newborn's first poo. It is thick, sticky and black or dark green, because it filled the baby's intestines before birth. That is why black poo in the first days after birth is normal. According to the NHS, some babies pass meconium during or just after birth and the rest within the first 48 hours. Medycyna Praktyczna, a Polish medical publisher, says that all healthy newborns pass meconium within the first 3 days after birth, 90% of them on the first day.
The UK NICE postnatal care guideline points out that if a baby has not passed meconium within 24 hours of birth, this may indicate a serious disorder and requires medical advice. If you go home before your baby has passed meconium, staff should tell you that if it does not happen within 24 hours of the birth, you need to contact a doctor or midwife.
According to Medycyna Praktyczna, the passing of meconium should be recorded in the child health book (książeczka zdrowia dziecka). It is worth checking for this entry when you are discharged.
How does newborn poo change in the first days?
Meconium is followed by what are called transitional stools. Medycyna Praktyczna describes them as green and loose, lasting a few days after the meconium has passed. The NHS says that in a breastfed baby the black, tar-like poo should be changing to a lighter, loose, greenish poo by day 3, and after a few days the poo turns yellow or mustard-coloured.
This change of colour is natural and needs no action. According to the NHS, a breastfed baby aged between 4 days and 6 weeks who is feeding well should pass at least 2 yellow poos a day.
What does breastfed poo look like compared with formula-fed poo?
What poo looks like depends mainly on how your baby is fed. The descriptions from the NHS, the AAP and Medycyna Praktyczna can be summed up like this:
| Feature | Breastfed | Formula-fed |
|---|---|---|
| Colour | yellow or mustard, sometimes greenish | yellow, tan or darker brown; some formulas turn poo dark green |
| Texture | loose, mushy or runny, often with small bits that look like seeds | firmer and paste-like, but according to the AAP no firmer than soft modelling clay |
| Smell | mild, sometimes slightly sour | stronger |
If you switch from breastfeeding to formula or start topping up with formula, poo usually becomes darker and thicker, more like a paste. Medycyna Praktyczna adds that once formula is introduced, a baby may pass stools with more effort, grunting and straining. The AAP notes that poo can also turn darker when a baby is given an iron supplement.
How many times a day does a newborn poo?
Frequency varies a lot from baby to baby. According to the AAP, many newborns poo soon after each feed, because a full stomach sets the gut to work. Approximate figures from the sources:
| Age and type of feeding | What is typical |
|---|---|
| First 1-2 days | meconium, black or dark green; no meconium within 24 hours requires medical advice (NICE) |
| First week of life | 2 or more poos a day (NHS) |
| Breastfed, from day 4 to 6 weeks | at least 2 yellow poos a day, often after every feed (NHS); up to 7-10 times a day (Medycyna Praktyczna) |
| Breastfed, after about 6 weeks | poo may come only every few days (NHS); some babies aged 3-6 weeks poo once a week and this is normal as long as the stools are soft and the baby feeds well and gains weight (AAP) |
| Formula-fed | up to 5 times a day as a newborn, often once a day after a few months (NHS); at least once a day (AAP); 2-3 stools a day (Medycyna Praktyczna) |
A change in what is usual for your baby matters more than the number itself. The NHS advises talking to a doctor if you notice a definite change, for example the poo becomes very smelly, very watery or harder, especially if there is blood in it.
Which newborn poo colours are a cause for concern?
Yellow, mustard, green and brown in various shades are all normal colours for baby poo. According to the AAP, green stools are not unusual and should not cause alarm, and occasional changes in colour and consistency are normal. The ones that need attention are white or pale grey poo, blood, and black stools after the meconium has passed.
| What you see in the nappy | What it may mean | What to do |
|---|---|---|
| White, pale grey or very pale, washed-out poo | no bile reaching the gut; possible liver or bile duct disease, including biliary atresia | contact a doctor straight away, do not wait for the next visit |
| Red streaks of blood on the surface of the poo | according to the AAP, most often a minor irritation or small tear of the anus | the AAP advises urgent medical assessment for any baby under 12 weeks with blood in the stool |
| A lot of blood in the poo, or blood passed without any poo | heavier bleeding whose cause a doctor must find | the AAP advises going to the emergency department straight away |
| Black, tarry poo after the meconium has passed | blood from the stomach, which stomach acid turns black | the AAP advises urgent medical assessment for tarry, black stools; dark green poo is normal |
| Very watery poo that suddenly comes much more often | diarrhoea; according to the AAP, the signs are a sudden rise to more than one stool per feed and a lot of water in the stool, and the main risk is dehydration | contact a doctor; if a baby under 3 months also has a temperature of 38°C or more, call a doctor straight away |
| Hard, dry lumps | according to the AAP, this may mean the baby is not getting enough fluid or is losing fluid through illness, fever or heat | tell your midwife or doctor; see the section on constipation below |
Pale poo is the most important of these signs. Dr Piotr Czubkowski of the Children's Memorial Health Institute in Warsaw (Instytut Pomnik-Centrum Zdrowia Dziecka) explains in Medycyna Praktyczna that the colour of stool comes from bile pigments that reach the gut with the bile. When bile cannot drain, stools are grey or pale yellow, which should be a warning sign for parents and doctors. This can be a sign of biliary atresia, a blockage of the bile ducts: a rare disease affecting about 1 in 18,000 children, which usually shows between the 2nd and 6th week of life and most often leads to cirrhosis of the liver.
Other signs are jaundice that lasts longer than usual, dark urine (in young babies urine is almost colourless or pale yellow) and prolonged bleeding from the belly button or elsewhere. Surgery gives the best results in babies operated on before 2 months of age, so if you notice these signs at home, contact the doctor at the newborn unit or your family doctor immediately. The NHS also notes that pale poo can be a sign of jaundice. Very pale, washed-out poo can be hard to tell apart from the normal yellow poo of a breastfed baby, so if you are unsure, show the nappy to your midwife or doctor.
Is my newborn constipated if they have not done a poo?
Usually not. The NHS says that a baby is not constipated as long as their poos are soft, even if they have not done one for a few days. It is also normal for babies to strain or even cry when doing a poo. Medycyna Praktyczna describes infant dyschezia: the baby strains, goes red and grunts because it is trying to pass stool and tightening the anus at the same time, and then passes a completely soft poo. This is harmless and usually goes away after a few months, and true constipation is rare in babies.
According to the NHS, signs of constipation can include:
- dry, hard, lumpy or pellet-like poos,
- finding it difficult to poo, and poos that are larger than usual,
- pooing fewer than 3 times in a week,
- unusually smelly wind and poo,
- being less hungry than usual, a firm tummy, and sometimes less energy and grumpiness.
Infrequent poos in an older breastfed baby do not mean constipation on their own, as long as they are soft and the baby feeds well and gains weight. The first weeks are different: the NHS says that if a breastfed baby aged between 4 days and 6 weeks has not done a poo in the past 24 to 48 hours, you should speak to your midwife, as this may mean they are not getting enough milk. For a formula-fed baby, the AAP says fewer than one poo a day together with straining may be constipation.
If a formula-fed baby has hard stools, the AAP advises checking that you are making up the formula exactly as the instructions on the pack say. The NHS suggests that gently moving your baby's legs as if riding a bicycle and a gentle tummy massage can help. If things do not improve after a few days, talk to a doctor. Medycyna Praktyczna warns never to put a thermometer or any other object into a baby's bottom to stimulate a poo, because it can damage the lining of the anus and disturb the development of the bowel reflex.
What do nappies say about feeding, and when should a midwife or doctor see them?
The number of wet and dirty nappies is one of the simple signs of whether a newborn is getting enough milk. According to NICE, a breastfeeding assessment includes asking parents about the number of wet and dirty nappies, alongside whether the baby wakes for feeds and how their weight is changing. The Polish perinatal care standard lists the number of feeds, stools and wees per day and weight gain or loss as indicators of effective or ineffective breastfeeding, which are recorded in the medical notes on the ward. Medycyna Praktyczna says that in the first 2 days a newborn wees 2-6 times a day, and later as often as a dozen to 30 times.
Nappies are no substitute for weighing. Under the perinatal care standard, the POZ midwife (a primary care midwife funded by the NFZ, Poland's public health insurer) assesses and records, during the free postnatal home visits called wizyty patronażowe, among other things your baby's wees and poos, how feeding is going, weight gain and how yellow the skin is. You can show her a nappy and ask about anything that worries you. If you need an extra visit, you can also book a midwife privately.
Do not wait for the next visit, contact a doctor straight away if:
- your newborn has not passed meconium within 24 hours of birth,
- the poo is white, pale grey or very pale, especially if jaundice is lasting longer or the urine is dark,
- there is blood in the nappy, or black, tarry poo after the meconium has passed,
- the poo is very watery and much more frequent than usual, and your baby has a temperature or seems unwell.
Talk to your midwife if a breastfed baby aged between 4 days and 6 weeks has not done a poo for 24-48 hours, or if the poo is hard and dry.
