What is physiological reflux?

Reflux by definition is the action of something going the wrong way through a valve. So, reflux can occur in your kidney, in your car engine, and in your stomach! When a baby has reflux in their stomach, this basically means the contents of their stomach (a mix of milk and stomach acid) is coming back up through the sphincter into the oesophagus. This can cause some discomfort in babies and adults, but for the most part is a physiological phenomenon that occurs in young, otherwise healthy babies with no obvious illness, or distress in the baby. The main reason reflux is so common is because baby’s digestive systems are very immature. 

How common is physiological reflux?

It’s very common – affecting about half of babies in the UK at some point, and it may not even be that it is experienced at every feed, every day. It can happen a few times a day or only once a day. It could be just a little bit, or a significant amount of milk coming back up. Some degree of posseting or vomiting is perfectly normal in most babies, and they will likely have no issues bringing it up – even if it doesn’t come all the way up! Around half of all babies aged 0-3 months will spit up at least once a day, this usually peaks between 2-4 months, and for most babies this is outgrown by 12 months.

What’s the difference between physiological reflux and projectile vomiting?

There is a big difference between physiological reflux and projectile vomiting, which is more serious. Lots of parents worry that babies spitting up large volumes of milk rapidly means they are projectile vomiting; however, this is really uncommon and projectile literally means “a missile designed to be fired from a gun” – projectile vomit will likely fire across the room at rapid speed and cause quite a lot of distress for the baby.

If you are caring for a newborn that is projectile vomiting then seeking urgent medical advice is important.

You can be reassured that if your baby is gaining weight well, spitting up without discomfort and is generally content, then your biggest problem is likely to be the amount of laundry you need to do!

Watch our free on demand masterclass, and discover how to support families whose babies experience symptoms of colic, reflux and infant allergies, without resorting to medication…

So, reflux can occur in your kidney, in your car engine, and in your stomach!