Poos and wees

It might not be fun but checking what is in your baby's nappy is important. It can tell you a lot 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. It doesn't smell bad.

Formula-fed babies' poo is firmer. It is darker brown in colour and smellier.

Some infant formulas can make your baby's poo dark green. If you change from breast to formula feeding, your baby's poos will become darker. They will change from runny to more like a paste.

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 doing a poo.

In the early weeks (up to about 6 weeks)

Most babies will do at least 3 poos a day, and sometimes one after every feed. If your baby is doing less than one poo a day, it could mean they need to be fed more often.

From around 6 to 8 weeks

The number of poos can vary. Some babies still poo after most feeds, while others might only poo every few days – even up to 10 days apart. This can be normal as long as the poo is soft and not hard or dry.

When changing your baby, you should look for:

• poo should be soft and easy to pass, even if it's less frequent
• hard, dry poos or signs of discomfort may mean constipation – speak to your doctor or child health nurse if you're concerned
• colour can range from mustard yellow to greenish or brown, depending on feeding and age

Speak to your doctor or child health nurse if:

• your baby seems unwell, has very hard poos, or you notice blood in their nappy
• your baby hasn't pooed for more than 10 days and seems uncomfortable

Parents sometimes find different colours of green in their baby's nappy.

Breastfed babies can make bright, frothy green poo. This can happen because they are getting too much foremilk. It can also happen if mum is swapping from breast to breast during feeds. Try feeding from just one breast at a time until the breast is drained. This can help to make sure your baby is 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 formula. Check the formula to see if it contains an iron supplement. Speak to your child health nurse or doctor about possibly changing the formula you use.

From day to day, and week to week, your baby's poos will probably change. They can change if your baby starts to have top-up formula feeds. 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 biliary obstruction which can cause jaundice. If you're worried, speak to your midwife or child health nurse.

A single streak of blood in your baby's poo could be a sign of constipation. If you see more than one streak of blood, 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.

Sometimes parents think that their baby might be constipated. This concern can arise if the baby has not done a poo for a few days. You might get worried if your baby seems like they are straining when they do a poo.

Healthy babies under 6 months can sometimes strain and cry before doing soft poos. This is known as 'dyschezia'. It is not constipation unless their poos are also hard. If the poos are soft, it will resolve on its own.

As long as your baby's poo is soft, it's perfectly normal to go for a few days without doing a poo. You will also find that babies often strain or make noises when they poo. Sometimes they go red in the face and even cry when they are doing a normal poo.

Constipation can happen when a baby starts on solid foods. 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. If they are constipated, they might have a little tear in their anus (the end where the poo comes out). You should see your doctor or child health nurse to have them checked out.

Fully breastfed 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. It's important to follow the directions on the container of formula. This is to make sure the mix of powder and water is correct.

When it comes to diarrhoea, it can be harder to tell, as baby poo is already quite soft. If a baby's poo is 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 poos 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. Babies can easily become dehydrated if they don't get enough fluids.

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 may wee smaller amounts or less often.

Your baby is getting enough breast milk or formula if they have 6 to 8 wet nappies a day. The wee should be pale and not smelly.

If your baby is weeing a lot less than usual, see your doctor.

Your baby's wee should be light to dark yellow in colour. The wee will be darker when your baby is drinking less liquid. This is because the wee is more concentrated.

Weeing should never be painful. If your baby seems distressed when they wee, this may be a sign of an infection. It could also be another problem in your baby's urinary tract. Other signs of a problem in the urinary tract (Opens in new tab) can be:

• irritability
• vomiting
• drowsiness
• loss of appetite

Learn more about gastroenteritis in children (Opens in new tab). This factsheet from the Royal Children's Hospital is available in different languages.

For help with breastfeeding visit the Australian Breastfeeding Association website or call their helpline on 1800 868 268.

Ask your midwife, child health nurse or pharmacist for advice on choosing a baby formula.