Poos and wees
8-minute read
Key facts
- Checking the contents of your baby's nappy can tell you a lot about their general health.
- Breastfed babies' poo is usually runny, yellow and doesn't smell offensive.
- Formula-fed babies’ poo is firmer, darker brown and smellier.
- Diarrhoea is when your baby frequently passes unformed, watery poos and it is often caused by an infection.
- Babies under 6 months old should always be checked by a doctor if they have vomiting and diarrhoea, because they are at higher risk of dehydration.
What does baby poo look like?
It might not be fun, but checking the contents of your baby's nappy is can tell you so much about the health of your baby.
Your baby's poo will look and smell different depending on if they are breastfed or formula-fed. Breastfed babies’ poo is runny and doesn’t smell offensive. Formula-fed babies' poo is firmer, darker brown and smellier.
Some infant formulas can also make your baby's poo dark green. If you change from breast to formula feeding, you'll find that your baby's poos become darker and more paste-like.
The first 6 weeks
During their first 6 weeks of life, both breast-fed and formula-fed babies will have generally have poo that is either yellow or green. Breast-fed babies tend to have softer, runnier poo while formula-fed baby poo is a little bit firmer.
Your baby's first poo (or stool) is called 'meconium'. It is sticky and greenish black.
After a few days the poo will change to a yellow or mustard colour.
In the next few weeks, you can expect the colour and shape, as well as how often they poo, to change.
Breastfeeding mums might find a bit more variety in the nappy because your diet and any medication you are taking can affect your baby's poo.
Why is my baby's poo green?
Parents sometimes find varying shades of green in their baby’s nappy.
Breast-fed babies can produce bright, frothy green poo, usually because they are getting too much foremilk or because mum is swapping from breast to breast during feeds. Try feeding from just one breast at a time until the breast is drained to make sure your baby is also getting the rich hindmilk.
If your formula-fed baby’s poo is green, it could just mean they are getting a lot of iron in their feed. Check the formula to see if it contains an iron supplement and speak to your child health nurse or doctor about possibly adjusting which formula you use.
How often should my baby do a poo?
Some babies fill their nappies at or around every feed. Some, especially breastfed babies, can go for several days or even up to a week without a bowel movement.
Both are normal. It's also normal for babies to strain or even cry when passing a poo. Your baby isn't constipated as long as their poos are soft, even if they haven't passed one for a few days.
Is it normal for my baby's poos to change?
From day to day, week to week, your baby's poos will probably vary. If you notice a significant change of any kind, you should talk to your doctor or child health nurse.
Pale (white or near white) poos may be a sign of jaundice. If you're worried, speak to your midwife or child health nurse.
While a single streak of blood in your baby’s poo could be a sign of constipation, if you discover more than one streak, you should see your doctor immediately.
It’s also a good idea to take your baby’s nappy, or a poo sample, to show the doctor.
How can I tell if my baby is constipated?
Many parents often think that their baby might be constipated, either because they haven't passed anything for a few days or because they might look like they are straining when they go.
Healthy babies under 6 months can sometimes strain and cry before passing soft poos. This is known as 'dyschezia' and unless their poos are also hard, this is not constipation and will resolve on it's own.
As long as your baby's poo is soft, it's perfectly normal to go for a few days without doing one. You will also find that babies often strain, make noises, go red in the face and even cry when they are doing a normal poo.
Signs of constipation include:
- hard and dry poo
- poo that is firm and pebble-like
- your baby being upset
- a small streak of blood
Seeing a streak of blood might be alarming, but if they are constipated, they might have a little tear in their anus. You should see your doctor or child health nurse to have them checked out.
Fully breast-fed babies shouldn't get constipated. Even if they are not feeding as often, their poo should still be quite soft. Constipation is more common in babies who are formula-fed, so it's important to follow the directions on the container to make sure the mix of powder and water is correct.
How can I tell if my baby has diarrhoea?
When it comes to diarrhoea, baby poo is already quite soft and runny, particularly before the baby starts on solids. But if it becomes more runny and more frequent than usual, it could be diarrhoea.
Some signs to look out for include:
- poo that is quite watery
- doing more than usual
- your baby is being unwell, especially if they are vomiting
- your baby not wanting to feed
If you think your baby has diarrhoea, speak to your doctor or child health nurse since babies can easily become dehydrated if they don't get enough fluids.
Severe dehydration is a medical emergency and can be fatal. If your baby shows signs of severe dehydration, seek urgent medical attention.
How often should my baby wee?
Your baby may urinate (wee) as often as every 1 to 3 hours or as infrequently as every 4 to 6 hours. If your baby is unwell, or it is very hot outside, your baby’s may wee smaller amounts or less frequently.
If your baby is weeing a lot less than usual, see your doctor.
What does baby wee look like?
Your baby’s wee should be light to dark yellow in colour. The wee will be darker when your baby is drinking less liquid and the wee is more concentrated.
When should my baby see a doctor?
Weeing should never be painful. If your baby seems distressed when they wee, this may be a sign of an infection or another problem in your baby’s urinary tract.
Blood in your baby’s wee is not normal. If you see blood in your baby’s wee, you should contact your doctor. If there are any other symptoms, such as abdominal pain or bleeding in other areas, your baby will need immediate medical attention.
Speak to a maternal child health nurse
Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.
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Last reviewed: March 2023
