The Ultimate Baby Poo Decoder: Your Visual Guide to What's Normal (and When to Worry)

Parents, we've all been there. You change your baby's nappy, and then… there it is. A masterpiece of sorts, but one that raises a hundred questions. Is that poo colour normal? Should it be that runny? Why does it look like… that?! and instinctively reaching for your phone. Well, forget the frantic searching. Aptaclub has a new AI-powered tool that helps you decode your baby's poo. It's called the Aptaclub Poo Checker, and it's designed to give you peace of mind, one nappy at a time. So, if you've got questions about your baby's poo, you can just Poogle It!

No more whispering about nappy contents or sending questionable photos to your best friend. This tool is here to empower you with information, drawing on our 50 years of scientific expertise in infant nutrition and immune system1. Let's dive into the fascinating (and sometimes baffling) world of baby poo and learn what typical and normal baby stool looks like2.

Understanding your baby's poo is a bit like learning a new language – the language of their gut. What comes out tells a story about their diet and what’s going on inside, from how they're digesting their feeds to patterns that might point to how their body is handling certain foods. For parents, baby bowel movements and gut-health are a constant topic of conversation, and for good reason. They are a primary indicator of your baby’s well-being3, 4.

We're going to break down the common types of baby poo you'll encounter, what's typical for newborn poo and older babies, and when it's time for a chat with your GP or paediatrician.

When your newborn arrives, their first few poos will be unlike anything you've seen before. This is completely normal and expected.

Meconium: This is normal for your newborn baby's very first poo, usually passed within the first 24-48 hours after birth⁵. It's thick, sticky, and has a tar-like, black or very dark green appearance. It's essentially made up of everything your baby ingested in the womb – amniotic fluid, mucus, and old cells. Don't worry, it's a sign that their bowels are working properly.

Transitional Stool:  After meconium, usually around days two to four, your baby's poo will start to change. This is called transitional stool. It will become lighter in colour, often a dark green or brownish-green, and less sticky, with a looser texture. This change indicates that your baby is now digesting breastmilk or formula⁶.

Once your baby is past the meconium and transitional phases, their stool will settle into a more consistent pattern, but it will still vary depending on their feeding method.

If you're breastfeeding, your baby's stool will often look quite distinct⁴.

Stool Colour: Typically, it's a mustardy yellow colour, sometimes with a slightly orange or green tinge.

Stool Consistency: Often described as loose, watery, or even seedy, resembling cottage cheese or grainy mustard. It might also be quite frothy. This is perfectly normal for breastfed infants⁷.

Smell: Usually mild and sweet-smelling, not unpleasant.

Frequency: Can vary widely. In the early weeks, a breastfed baby might poo several times a day. As they get older, it's not uncommon for them to go several days, or even a week, between bowel movements. This is generally fine as long as the poo remains soft when it does arrive, and your baby is gaining weight and seems comfortable⁸.

For babies fed on infant formula, their poo tends to be a bit different⁴.

Stool Colour: Usually a pale yellow, tan, or light brown colour.

Stool Consistency: Often thicker than breastfed poo, more like peanut butter or a soft paste, but still soft.

Smell: Stronger smelling than breastfed poo, and generally more pungent.

Frequency: Formula-fed babies typically poo less frequently than breastfed babies, often once a day or once every other day.

If your baby is combination feeding, their poo can be a mix of the above, often leaning towards the characteristics of formula-fed poo due to the differences in digestion⁹. It's a spectrum, and changes are to be expected.

These are the most common colours for healthy breastfed and formula-fed babies. It signifies normal digestion⁴.

Green baby Poo is a frequent cause of concern for parents but is often completely normal.

Dark Green Poo: Common in the transitional poo phase. Also seen in formula-fed babies, especially those on iron-fortified and extensively hydrolysed formulas.

Bright Green/Frothy Green Poo: In breastfed babies, this is most commonly due to faster-than-normal movement through the gut, so bile doesn’t have time to break down fully¹⁵. This can give the poo a green appearance. This isn’t usually a concern, especially when your baby is otherwise feeding and growing. In both breastfed and formula-fed babies, green poo can sometimes be loose, but this is normal.  If persistent or present accompanied by other symptoms, it's worth checking with a healthcare professional.

This is a red flag baby poo and requires urgent medical attention. Very pale or chalky white or pale grey poo can indicate a serious liver problem where bile isn't reaching the intestines^{11, 12}.

Any red streaks or flecks of blood in your baby's poo should be investigated immediately by a doctor¹³. It could be from a tiny anal fissure (a common cause, especially if the baby has been constipated), but it can also indicate a milk protein allergy or a more serious intestinal issue.

Once your baby is past the meconium stage, black poo can be a cause for concern as it might indicate digested blood from higher up in the digestive tract¹³. Seek medical advice if you observe this.

Often seen with very green poo in breastfed babies which can happen when milk moves through their tummy a little too quickly. It’s usually nothing to worry about if your baby is otherwise well, feeding happily, and gaining weight.

Slimy, jelly-like streaks of mucus in the nappy can be unsettling. A small amount might be normal if your baby has a lot of saliva due to teething. However, significant or persistent mucus, especially with blood, can point towards an infection or an infant food sensitivity/allergy⁷.

Your baby’s poo is usually yellow or brown. If they have pale or very light stools, especially in the first couple of weeks, this could be a sign of jaundice or an issue with how their liver or bile ducts are working. If this happens, contact your GP, midwife, or health visitor for advice straight away²⁰.

Once your baby starts weaning and introducing solids, it's very common to see bits of undigested food in their poo. Their digestive system is still maturing, and some foods simply pass through intact. This is usually nothing to worry about.

This is a clear sign of constipation. Your baby may also strain, cry, or show discomfort or straining when trying to poo, or your baby might not be pooping at all¹⁴.

As mentioned, this is typical for breastfed babies. It can also be normal for formula-fed babies as long as it's not excessively watery and frequent (which could indicate baby diarrohea).

Again, every baby is different, but their bowel movements may well follow a similar pattern.  

From their first poo to nappy habits when weaning, here’s what you can expect in your little one’s first year¹⁶.

Navigating the world of baby stool can feel overwhelming, especially when you’re tired and worried. This is exactly why Aptaclub has developed, in collaboration with parents and HCPs, following 50 years of research in infant health and the immune system, the revolutionary AI Poo Checker  — designed* to give you results in those moments of nappy uncertainty. 

Here’s how it works: you simply take a photo of your baby's nappy, and our advanced AI-powered tool will do the rest. The AI will "decode" your baby's poo to empower you with instant analysis, giving you:

• Valuable Information: On the type of stool and potential causes, including stool colour charts.
• Detailed Guidance: To help you understand what it may mean for your baby.
• Confidence & Reassurance: A recent study highlighted that while parents often try to assess their baby's stool, AI can be significantly more accurate (95.8% agreement) compared to parents' self-assessments (66.9% agreement)¹². This means less guesswork for you and more reliable information.

Our tool aims to answer that commonly asked question, "Is my baby's poo normal and healthy?" by covering all the topics we’ve discussed above and more. It helps to alleviate parental anxiety and to support the dialogue between parents and healthcare professionals through a user-friendly and accurate, validated digital health tool. 

Don't let nappy worries keep you up at night. "QUESTIONS ABOUT YOUR BABY'S POO? POOGLE IT!".

^{*The Aptaclub AI Poo Checker is not a diagnostic tool and does not provide medical insights about your baby’s digestive health. It does not replace the advice of a healthcare professional.}

Your baby’s poo will probably be a little runny for the first 6 months while they’re only having milk and not solid food. Some babies have runnier poo than others, but you’ll soon see what’s normal for your little one. 

If your baby has diarrhoea, their poos might become:¹⁸

• A lot more runny or watery than usual
• Smellier than normal
• More frequent

It’s pretty common for babies and children to get stomach bugs that cause diarrhoea, and this is usually nothing to worry about as long as they stay hydrated¹⁸. If you’re worried, you can always speak to your health visitor or GP.

After a few weeks, it can be normal for your baby to go for a day or two without having a poo.

Breast milk is a natural laxative, and in the first six weeks, your breast-fed baby will likely be having at least 2 poos a day. If they don’t have a poo in the past 24-48 hours, have a chat with your healthcare professional⁶.

If your baby ius formula-fed, they can sometimes go for up to a week without having a poo¹⁹. Our expert midwife says ‘your baby will soon find their own pattern. As long as they’re not showing the signs of constipation them, it’s about recognising what’s normal for them’.

You’ll be able to tell your baby’s constipated if ¹⁷:

• Their poos are small, dry or hard
• Their poos and wind are smellier than normal
• Their tummy feels firm

If you think your baby is constipated or they’re struggling to poo, try lying them down and gently moving their legs as though they’re riding a bicycle, or try giving them a gentle tummy massage. If your baby is on solid foods, be sure to incorporate enough fibre into their diet. If that doesn’t get things moving after a few days, speak to your healthcare provider¹⁷.

"In the first few days and weeks of life, it’s always good to follow the guidance your midwives give about the ever-changing colours, textures and smells of your baby’s poo", says our expert midwife. "You’ll be asked about how many poos your baby is producing within a 24-hour period and what colour it is, as this can tell us a lot about your baby’s health."

An unusual poo here or there is usually nothing to worry about, but for peace of mind, here are some of the things you might spot and what they could mean.

Remember, you know your baby best. Trust your gut – it’s always best to check in with your health visitor if you think something’s not quite right. As Seb’s mum says, "if you think that something’s not quite right, whether it’s your baby’s poo or something else, seeking advice is always the right call, even if that’s just to get peace of mind that there’s nothing to worry about."

If you notice white specks of cottage cheese like curds in your baby’s poo, this is likely to be the result of your baby’s milk not being fully digested. It’s more common in breast fed babies (because breast milk has a higher fat content), but it can be seen in formula-fed baby poo, too²¹. "As long as your baby is feeding well", advises our expert midwife, "then this is nothing to worry about."