Newborn Diarrhoea

How to tackle this common condition in tiny tummies.

In Newborn

    3-minutes read

    At a glance

    Contact a healthcare professional if you have any concerns about baby’s health

    Diarrhoea in babies may clear up on its own within 24 hours – if not, seek medical advice


    Keep fluids topped up when baby has a runny tummy

    Learn more about common baby feeding issues by taking our symptom checker

    Baby’s poos will probably vary in texture and colour from day to day or week to week. Watery or loose poo is common in babies, especially if they’re breastfed. If your baby is otherwise well (no fever, vomiting or distress), it is likely the diarrhoea will settle within 24 hours. If there’s an obvious change, such as the poo becoming very smelly, very watery or harder, and particularly if there’s blood in it, talk to your GP, health visitor or public health nurse.

    Symptoms of diarrhoea in babies

    Newborn diarrhoea can be quite common as their little digestive systems are still developing even after they are born. Baby poo is relatively runny-looking most days anyway, especially if you’re breastfeeding. Only you know what's really normal for your baby. Here are some symptoms to look out for:

    • If your baby is pooing more often than usual, or their poos are much more watery than normal

    • Fever

    • Loss of appetite

    • Fewer wet nappies and the pee is strong-smelling when it finally makes an appearance – this is a sign of dehydration

    What causes newborn diarrhoea?

    Man cradling newborn baby on his shoulder

    Your baby’s immune system is still developing so they could be a bit more vulnerable to viral infections, which is why the most common cause of diarrhoea is a stomach bug. Immunisations can sometimes cause your baby to have a mild case of diarrhoea too. If your baby’s diarrhoea lasts longer than 24 hours seek medical advice.

    Your baby may be more prone to newborn nappy rash if they have diarrhoea, so change nappies more often and use a barrier cream each time to protect their delicate skin. If it gets sore, ask your pharmacist for a nappy rash cream which should help calm things.

    How to treat your newborn’s diarrhoea

    • Try to keep baby home for plenty of rest (and fewer public nappy leakage catastrophes).

    • Carry on breast- or bottle-feeding your baby – if they're being sick, try feeding smaller amounts, more often.

    • Baby diarrhoea leads to dehydration so try to top baby up with fluids more often. Give babies on formula small sips of cool boiled water between feeds in a separate bottle. Don’t dilute their normal feed as this can affect their nutrition. If breastfeeding offer extra feeds throughout the day.

    • Do not use anti-diarrhoea medicines for babies or infants unless directed by your GP.

    If you are concerned or unsure, speak to a healthcare professional such as your GP, health visitor or public health nurse. If you feel your baby is unwell and you notice any signs of dehydration, fever, vomiting - or if diarrhoea has lasted more than 24 hours - always get your GP’s advice. Our Careline team are also able to help.

    Could diarrhoea be a symptom of lactose intolerance?

    Newborn displaying discomfort

    Lactose intolerance is when your baby can’t digest lactose, a natural sugar found in milks. In the early weeks of life, or after a tummy bug, some little ones can experience temporary lactose intolerance. It is relatively common in young babies but usually sorts itself out in a few weeks. Common signs to look out for:

    • Diarrhoea

    • Wind

    • Abdominal bloating and pain

    • Discomfort and crying

    Read our article on lactose intolerance for more information. If you are concerned baby’s diarrhoea could be a sign of lactose intolerance talk to your GP who might refer you to a dietitian for specialist advice.

    Careline online

    Need some help? Our Careline team are online to answer your questions

    IMPORTANT NOTICE: The best way to feed a baby is to breastfeed, as breast milk provides the ideal balanced diet and protection against illness for your baby and also many non-nutritional benefits for both baby and mother. We recommend that you speak to your healthcare professional when deciding on your choice of feeding your baby. Professional guidance should also be sought on the preparation for and maintenance of breastfeeding. If you do choose to breastfeed, it's important to eat a healthy, balanced diet. Infant formula is intended to replace breast milk when mothers choose not to breastfeed or if for some reason they are unable to do so. A decision not to breastfeed, or to introduce partial bottle-feeding, will reduce the supply of breast milk. If for any reason you choose not to breastfeed, do remember that such a decision can be difficult to reverse. Using infant formula also has social and financial implications which must be considered. Infant formula should always be prepared, used and stored as instructed on the label, in order to avoid risks to a baby’s health.

    Feeding issues symptom checker

    Feeding issues symptom checker

    Experiencing feeding issues with your newborn?
    Get help narrowing down the cause with our symptom checker.

    Find out more

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