Baby diarrhoea

Of all the things you expected to worry about when bringing a baby into the world, their poo, and specifically baby diarrhoea, probably didn’t rank very high on your list.

In reality, as a parent, it’s sometimes hard to remember a time when discussions about baby poo and its presentation weren’t a part of everyday life.

Here we’re exploring some of the more common enquiries you might have as a parent dealing with this particular conundrum, such as, what does baby diarrhoea look like? How long does diarrhoea last for a baby? And just what can you do to help? 


What does baby diarrhoea look like?

The first thing to remember is that it’s not unusual for newborn babies to have the odd runny poo. Part of establishing whether or not you’re dealing with baby diarrhoea vs ‘normal’ poo is to ask the question, what does baby diarrhoea look like? The answer isn’t as straightforward as you might think.

The fact is that when it comes to poo, every baby is different. It comes in a variety of different smells and consistencies, not to mention frequencies. Ultimately, it’s only after getting to know your baby’s toilet habits that you’ll be able to say what’s normal, and what’s not so normal.

As a general rule, if your baby’s poo is particularly foul smelling and more frequent than normal, or is streaked with blood or mucus and is watery1, there’s a good chance that your baby has diarrhoea.

Diarrhoea in breastfed & formula fed babies

The nature of baby diarrhoea can vary depending on whether your baby is breast or formula fed. So, what’s the difference?

If your baby is breastfed, they may have a poo after (or even during) every feed, or poo as little as once a week. Formula fed babies on the other hand, may poo anywhere between five times a day, decreasing to once a day as they grow.2 But this is not a rule, every baby is different, and every baby has their own normal when it comes to their bowel movements.

As such, determining whether or not your baby is suffering with diarrhoea is no mean feat. It all comes down to understanding your baby’s bowel habits. So whether they’re breast or formula fed, if your baby is pooing more than they usually would3, or you’re dealing with yellow watery diarrhoea, then this could be a sign of tummy trouble. 

Given that baby poo comes in a variety of different colours, consistencies and frequencies, it really comes down to trusting your gut about what’s normal for your baby.

What causes diarrhoea in babies?

There are a number of things that can cause baby diarrhoea. But mostly it’s due to a viral infection, the most common being rotavirus4. It can also be caused by E.Coli or salmonella.

But there are other causes, too. For example:


Antibiotics can cause an imbalance in the bacteria that live in your baby’s gut5 which might result in them experiencing diarrhoea.

Some immunisations can also cause diarrhoea for a few days, but the symptoms are usually mild and settle within a few days6. If you find that symptoms don’t settle and your baby has constant diarrhoea, it’s important that you seek advice from your GP.


If your baby has diarrhoea, they could potentially have an allergy to a particular food, the most common one being cow’s milk allergy . Approximately 7% of babies under the age of 12 months suffer from a cow’s milk allergy, which occurs when your baby has a reaction to the proteins found in cow’s milk7

How long does diarrhoea last for babies?

There’s no one size fits all when it comes to how long your baby’s diarrhoea will last. In general terms, diarrhoea will last anywhere from a couple of days up to a week8. If your baby’s symptoms haven’t cleared by then, always consult your GP for further advice.

How to stop diarrhoea in babies

There’s no miracle cure for baby diarrhoea. In most cases, medication won’t be required and it’s simply a case of riding it out and helping your baby to cope with the symptoms at home.

Here are a few things you can do to help your baby’s immune system fight the virus, and get them back to their usual self as soon as possible9:

  • Continue to feed your baby with their usual milk, be it breast or formula milk.
  • If your baby is weaning, provide them with small sips of water in between feeds.
  • Be sure to change your baby’s nappy on a regular basis to avoid nappy rash and irritation.

A note about dehydration

Babies can be susceptible to dehydration, particularly if they’re experiencing diarrhoea and vomiting. Things to look out for include10:

  • Urine that’s dark in colour and strong in smell.
  • Fewer tears and/or wet nappies.
  • A sunken fontanelle (the soft spot on top of your baby’s head).
  • Blotchy and cold hands and feet.

If you suspect that your baby is dehydrated, you should always seek the advice of a medical professional. In the meantime, continue to feed your baby breast or formula milk, and give them regular sips of water only if they are over 6 months or weaning. 

There's blood in my baby's diarrhoea stool

You should always contact your GP if there's blood in your baby’s stools. You should also seek medical advice if you’re concerned about your baby having abdominal (tummy) pain, or if you feel the symptoms are progressing and worsening.

Do babies get diarrhoea while teething?

Whilst it’s very common to associate teething with diarrhoea, the NHS is clear that there’s no evidence to support this11.

Can I give a baby with diarrhoea starchy foods?

In a nutshell, yes. Starchy foods such as pasta, crackers and bread can be consumed by your baby if they’re suffering with diarrhoea and you should offer them food as you normally would12.

I changed my baby's formula milk and now they have diarrhoea

If you’re formula feeding your baby, and you make changes to the milk that you use, it may take your baby’s tummy a little bit of time to adjust. However, if you think that it may be disagreeing with your baby, talk to your midwife or health professional13.

The ‘bottom’ line

Diarrhoea can be quite distressing and exhausting for parents but it's important to know that most of the time these symptoms will resolve in a couple of days. Upset tummies, temperatures and diarrhoea are something that you’re likely to have to deal with at some point on your parenting journey. But it’s important to know that whilst diarrhoea can be quite distressing and exhausting for parents, most of the time the symptoms will resolve in a couple of days.

However, if your baby’s symptoms are prolonged, and causing your baby significant distress, always contact your GP for help and advice.

Your baby's future health begins here

At Aptaclub, we believe that experience helps to build resilience; and that each new encounter, whether in pregnancy or after birth, can shape your baby’s future development. With our scientific expertise and one-to-one round the clock support, we can help you and your baby embrace tomorrow.

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Get in touch with our Careline experts

Our midwives, nutritionists and feeding advisors are always on hand to talk about feeding your baby. Need instant assistance? Our WhatsApp Customer Support team is here to help on-the-go!

  1. U.S National Library of Medicine. Medlineplus. Diarrhea in infants [online] 2019. Available at Accessed March 2021
  2. National Health Service (NHS) Derbyshire Community Health Services. Advice and Guidance: bowel movements [online]. Available at  Accessed March 2021.
  3. U.S National Library of Medicine. Medlineplus. Diarrhea in infants [online] 2019. Available at Accessed March 2021.
  4. National Health Service (NHS). Rotavirus vaccine overview [online] 2020. Available at  Accessed March 2021
  5. Mi Young Yoon et al. Disruption of the Gut Ecosystem by Antibiotics. Yonsei Med J. 2018 Jan 1; 59(1): 4–12.
  6. Centers for Disease Control and Prevention (CDC). Vaccine (drops) for Rotavirus [online] 2019. Available at Accessed March 2021.
  7. National Health Service (NHS). What should I do if I think my baby is allergic or intolerant to cow’s milk? [online] 2019.
  8. National Childbirth Trust (NCT). Diarrhoea and vomiting in babies [online] 2018. Available at,cases%20stops%20within%20two%20weeks%20. Accessed March 2021.
  9. National Health Service (NHS). Diarrhoea and vomiting [online] 2020. Available at Accessed March 2021.
  10. National Health Service (NHS). Dehydration [online] 2019. Available at Accessed March 2021.
  11. National Health Service (NHS). Baby teething symptoms [online] 2019. Available at Accessed March 2021.
  12. National childbirth Trust (NCT). Caring for a child with diarrhoea and vomiting [online] 2018. Available at Accessed April 2021.
  13. National Health Service (NHS). Types of formula [online] 2019. Available at,only%20formula%20your%20baby%20needs.&text=There's%20no%20evidence%20that%20switching,a%20midwife%20or%20health%20visitor. Accessed April 2021

Last reviewed: 09th June 2021
Reviewed by Oriana Hernandez Carrion

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