Debunking Baby Poo Myths: Understanding what's normal & what's not

Dr Shruti Nathwani

GP | Dual-qualified in General Practice (MRCGP) and Paediatrics (MRCPCH) | Digital Health Educator & Content Creator

Dr Shruti Nathwani is a General Practitioner with dual qualifications in General Practice and Paediatrics. She is passionate about making medicine more accessible and helping families feel confident about their health through clear, evidence-based advice.

Alongside her NHS work, Shruti runs The Children’s Medic, a digital platform dedicated to empowering parents with reliable information on child health and wellbeing. Her content reflects her clinical expertise and her own experience as a parent, creating a trusted and relatable space for families.

Her professional interests include Paediatric Medicine, preventative care, and health education. Outside of work, Shruti enjoys spending time with her family and finding creative ways to bring medical knowledge into everyday life.

First things first. Remember that every baby is different. Your instincts are always important when it comes to the health of your little one. Even with their poo.

So, let’s get into it. This is what you need to know when it comes to your baby’s stools.

The myth: Parents often worry that green stools are a sign of illness.

The truth: According to Dr Nathwani, green stools are very common in infants and usually nothing to worry about. In fact, research shows that nearly half of healthy term infants have green stools for at least one week during the first 17 weeks of life*.

Dark green poo is often seen in babies transitioning from meconium to normal stools, or in formula-fed babies, particularly those on iron-fortified or specialised formulas like hydrolysed formula.

Bright or frothy green poo can appear in otherwise healthy babies, caused by faster movement of food through the gut. Green stools in a happy, feeding and growing baby are usually harmless.

When to seek help:
You should get medical advice if your child has:

• Continuous green stool
• Fever
• Unusual sleepiness/lethargy
• Poor feeding/signs of dehydration
• Blood in the stool
• Persistent diarrhoea or vomiting

The myth: Many parents believe that any watery poo from their baby means that they have diarrhoea.

The truth: Often, baby poo tends to be runny a lot of the time, especially if they are breastfed. This means it can be quite difficult to spot the signs of baby diarrhoea . However, your baby may be suffering from diarrhoea if their poo is very watery and they’re pooing more often than normal.

When to seek help:

If your baby has watery poo and is also unwell with:

• High temperature
• Change in temperament
• Lighter nappies

The myth: A lot of parents worry that when their baby is teething, this can also cause diarrhoea.

The truth: According to the NHS, there is no medical evidence to support the claim that teething causes diarrhoea.

When to seek help: If your baby has diarrhoea, it’s important to seek medical help if they have other symptoms that are generally making them feel unwell, such as a high temperature and a change in temperament. 

The myth: Many parents worry if their baby doesn’t have a bowel movement daily, assuming infrequent pooing is abnormal or a sign of constipation.

The truth: Dr Nathwani says that bowel habits vary widely in infants. Newborns, particularly breastfed babies, can go several days without passing stool. This is usually not constipation if the stool is soft when it occurs and your baby is feeding well, gaining weight, and otherwise happy.

Formula fed babies tend to have more regular, but less frequent bowel movements.

When to seek help:

Contact a healthcare professional if your baby:

• Has hard, pellet-like stools
• Strains or appears in pain when pooping
• Refuses feeds or vomits
• Appears generally unwell or lethargic
• Has signs of dehydration

The myth: Often parents hold onto the hope that their baby’s poo will be ‘normal’ as soon as they start on solid foods.

The truth: Unfortunately, while your baby’s poo will change, it isn’t necessarily ‘normal’ – and by ‘normal’ we mean like adult poo. When you move your little one onto more solid foods, their stools tend to be brown or dark brown. They’re still mushy and often thicker than peanut butter. And they’re also smellier too.

Occasionally, you’ll see identifiable chunks of food in the stool – this is often the case during weaning when your baby is still learning to chew properly. Sometimes, the poo will even take on the colour of the food, whether they’ve been eating carrots or beetroot.

When to seek help: If your baby’s poo has consistently undigested food in it. This is important to check that your baby’s intestines are working, and they get the nutrients they need from the food they eat.

The myth: Many parents believe that smelly baby poo  may suggest that their baby has a health problem.

The truth: Baby poo does smell. Breastfed babies tend to do poos with a fairly weak, sweet smell, but formula-fed babies can often do stools with a stronger smell. You should only be concerned if the poo is very smelly and unusual for your baby.

When to seek help:

You should get medical assistance for your baby if their poo:

• Is offensive smelling
• Becomes consistently watery
• Has blood in it

The myth: Many parents worry if their baby’s poo looks different when formula-fed. This is especially the case if they switch from breastfeeding to formula feeding and their baby’s stools look different.

The truth: Formula-fed babies’ stools are often a little firmer and darker brown than breastfed babies. They may also be a little stronger-smelling. When you switch from breastfeeding to formula feeding, your baby’s stools might become darker and a little paste-like. This is completely normal and nothing to be concerned about.

When to seek help:

You should seek medical advice for your baby if their poo:

• Is consistently green
• Is chalky and light grey in colour
• Has blood in it

The myth: Poos that change from one nappy to the next suggest a health problem.

The truth: Even if poos change colour, it isn’t necessarily anything to worry about. If your baby has just started weaning, often their poo can take on the colour of the foods they’ve been eating. Even the occasionally purple-ish beetroot poo. Babies can also occasionally do green poos, but you shouldn’t worry.

When to seek help:

It’s important to seek medical attention if:

• Your baby is consistently doing green poos
• Some of their poos are chalky, pale grey or chalky white
• There is blood in their stool

The myth: Often, parents think that their baby is constipated if they’re straining and going red in the face when pooing.

The truth: Many babies go red in the face and appear to be straining when they’re pooing. But often this is them simply reacting to the sensations in their lower bowel as they poo. If their stools appear to be soft and come out easily, it’s not constipation. If your baby is in pain when they’re pooing, they will likely cry and tell you in this way.

When to seek help:

Seek medical advice if your baby:

• Is passing dry, hard or lumpy poo
• Crying or appearing unsettled
• Has unusually bad-smelling wind and poo, followed by other symptoms such as diarrhoea, poor feeding or signs of illness

The myth: Occasionally, parents believe that breastfed babies don’t need to poo often compared to formula-fed babies.

The truth: Often, breastfed babies often poo more frequently than formula‑fed babies, sometimes several times a day, although in some cases this can be once a day or every other day. But some bottle-fed babies can go every day too. Rather than looking into what’s ‘normal’ online, look at their poo when it does happen. If it’s soft, and they’re feeding well and gaining weight, then regularity is nothing to worry about. Yet, if they go longer than a couple of days without doing a poo, and the stools are hard, this could indicate constipation.

When to seek help:

Contact a medical professional if your baby:

• Has hard, pellet-like stools
• Strains or appears in pain when pooping
• Appears generally unwell or lethargic

If you’re still unsure if your baby’s poo doesn’t look right, simply upload a photo of your baby’s nappy. Our handy AI Poo Checker can help you understand what’s normal and when to seek advice. It’s quick, easy and reassuring.