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Vomiting in babies: what's normal?

A vomiting baby is never much fun for either you or the baby in question. Babies often get upset at a bout of vomiting and parents can feel worried – not to mentioned sleep deprived if a tummy bug goes on through the night. However, vomiting is generally a pretty normal occurrence in young babies and usually nothing to worry about. Here's a brief guide to things to look out for and how to care for your little one if he is unwell. Bring on the muslin cloths and baby wipes.

By Mumsnet HQ | Last updated Mar 20, 2023

Baby muslin

It is normal for young babies to regurgitate some milk or food after a feed – this is called possetting. However there are a number of other things which may cause vomiting – things like reflux and pyloric stenosis – as well as a few rare but serious issues, like meningitis, which have additional symptoms you should be aware of.

What is possetting?

When your baby regurgitates milk, it's called possetting. Possetting is quite common in young babies as their digestive systems are still developing and their stomachs are still small. Your baby's oesophagus is connected to his stomach by a small valve which allows milk into his tummy. The muscles that control this valve are not at full strength in young babies and so the valve occasionally opens and lets milk back up.

When your baby does posset, he will normally only regurgitate small quantities of milk – he might vomit, burp or dribble and cause the food to come up. From here on in, the muslin cloth is your new friend. Although possetting is completely normal, it may still frighten your baby so expect him to cry.

My son was happy, healthy and gaining weight but, boy, did he vomit all the time until he was one. I never went anywhere without a muslin cloth but there was nothing wrong with him.

Burping your baby regularly during a feed and keeping him upright for half an hour once he's finished can help to reduce possetting.

If your baby is bringing up large quantities of milk or food or is regurgitating after most feeds, then it's more likely that he has a bout of vomiting or has reflux.

How do I know if it's reflux?

About 50% of newborns under three months will experience some possetting but for a small number (about 5%) the regurgitation is persistent and painful. Gastro-oesophageal reflux can cause your baby to regurgitate not just milk but also strong stomach acid.

This might leave your little one in discomfort and you'll notice some of the following symptoms:

  • Crying after a feed and arching his back

  • Refusing to feed

  • Losing weight or poor weight gain

  • Restless sleep and waking frequently

  • Cough, sore throat or upset tummy

Some babies have silent reflux, where they have all the symptoms but regurgitate nothing. This can be harder to spot.

If your baby's symptoms are persistent or he is in a lot of discomfort, your GP can offer further advice. In many cases, an infant antacid formula can give your little one some relief and most babies grow out of reflux in their first year once the valve to their stomachs has strengthened.

Why is my baby vomiting so much after every feed?

If your baby suffers from forceful vomiting after each feed, then he could have pyloric stenosis. This occurs when the valve to the stomach thickens and doesn't let food into your baby's intestine properly.

Pyloric stenosis can begin any time from birth up to about four months, although it usually appears at around six weeks. Boys are more likely to have the condition and it's thought to be hereditary.

Symptoms of pyloric stenosis include:

  • Forceful or projectile vomiting within half an hour of a feed

  • Curdled, yellow vomit caused by stomach acid

  • Few or no dirty nappies because food is not being digested

  • Poor weight gain or weight loss

  • Stomach muscles looking strained during feeding

If you suspect that your baby has pyloric stenosis or he is showing any of the above symptoms, you should seek your GP's advice. Your doctor might diagnose your baby by observing him during a feed but sometimes tests and an ultrasound are required. Treatment involves a simple operation to cut through the thickened valve.

What else can cause my baby to vomit?

Babies can vomit for a number of reasons. More often than not it's something mild but occasionally vomiting can be a sign that your little one needs medical attention. Causes of vomiting can include:

Stomach bug

This sounds like a pretty generic explanation for something that can be frightening but stomach bugs like gastroenteritis are the most common cause of vomiting in babies. If the vomiting is accompanied by diarrhoea then you should contact your doctor who will advise you on how to treat your baby.

Infection or illness

Vomiting can be symptomatic of any number of childhood illnesses including scarlet fever, an ear or urine infection, cold or flu or even meningitis. If the vomiting is accompanied by other symptoms such as a fever or a rash, you should seek medical advice.


Vomiting is also one of the key signs of an allergic reaction, along with cold-like symptoms, a rash, diarrhoea or constipation. Vomiting as a symptom can be an indication that the allergy is food-related.

One of the most common food intolerances in babies is an allergy to the protein in cow's milk. Cow's milk allergy affects about 5% of children under three but many grow out of it. If you are concerned that your baby might be suffering from an allergy, always speak to your doctor.

My daughter was the pukiest baby ever. Some babies just vomit a lot. Looking back I think she was greedy and always took more milk than she needed, which didn't help. It got much, much better when she weaned.

Motion sickness

Like adults, babies can experience travel sickness when on a long car journey. Nausea can cause excess saliva to be produced, so he may dribble more than usual. He may also feel hot but look pale.

Excessive crying

If your baby is particularly upset, it may cause him to regurgitate or vomit.

When should I worry about my baby vomiting?

Excessive or untreated vomiting can lead to dehydration. If your baby is unwell with a bout of vomiting, you should take precautions to make sure he doesn't become dehydrated. Offer plenty of small, frequent feeds as they'll be absorbed quicker. If your baby is older, you could give him water in a sippy cup or bottle.

Signs of dehydration include sunken eyes, dark yellow urine, fewer wet nappies than usual and dry lips and mouth.

Vomiting can also be a sign of meningitis if accompanied by some of the following symptoms:

  • Refusal to eat

  • Agitation

  • Your baby being floppy or unresponsive

  • Fever

  • Stiff body

  • Bulging fontanelle (the soft spot on his head)

  • Red rash that initially looks like pin pricks but then turns blotchy

If your baby is vomiting accompanied by any of these other symptoms, do not wait for the rash to appear before getting help. You should seek urgent medical advice. If you think something is wrong, trust your instincts. Doctors will only ever be glad to send home a healthy child. You're not wasting anyone's time.


How can I help my baby feel better?

Most of the time, vomiting passes within 24 hours and is not related to anything serious. If your doctor advises caring for your baby at home, then try the following:

  • If breastfeeding, offer plenty of feeds. Not only will this keep him hydrated but the antibodies will help him to fight any illness.

  • If your baby is on solids, avoid any new foods. Stick to rice, mashed potato and toast – familiar, 'dry' foods that he can keep down.

  • Let him have plenty of sleep.

  • Do not give your baby fruit juice or fizzy drinks.

Anti-nausea medicines are not recommended for babies or children under the age of 12. However, your GP may recommend that you give your baby rehydration sachets. Always check with your doctor before doing this and always follow the instructions on the packet.