Baby projectile vomiting – is it pyloric stenosis?

Seeing your baby vomit can be worrying. While most babies vomit at some stage, it can be hard to know what’s normal and what isn’t.

If your baby is bringing up a little bit of excess milk after feeds, this is very common and usually nothing to be concerned about. When babies are small, the muscle (called the sphincter) at the top of their stomach is loose and can open easily, allowing milk to spill back out.

Reflux is also very common in infants, with an estimated 40-60% of newborns experiencing some degree of reflux in the first few months. It can cause pain and discomfort in some babies due to the irritation of stomach acid in the esophagus. Most babies outgrow reflux without requiring any medical intervention.

However, there is a rare condition that can cause a baby to vomit forcefully. It’s called pyloric stenosis and affects an estimated 1 in 500 babies.

What is pyloric stenosis?

Food normally moves from the stomach to the small bowel via an opening called the pylorus. If the muscles around this opening become bigger, they then squeeze it and cause it to become narrow. This results in food not being able to empty out of the stomach to the small intestine, because there’s not enough room for it to pass through, so it is often vomited back out.

The causes of pyloric stenosis are unknown, but genetic and environmental factors might play a role.

What are the signs and symptoms of pyloric stenosis?

If your baby is between two to six weeks of age, they may have pyloric stenosis if they:

• have recurrent and progressively more forceful. It may be projectile vomiting. The vomiting is non-bilious, which means it’s not bright green in colour.
• are often hungry after vomiting. It might seem like they’re hungry all the time.
• have weight loss or poor weight gain.

What are the risk factors for getting it?

It is more likely to happen in first-born male babies of Caucasian families, particularly if there’s a parental history of it.

How is it diagnosed?

If your baby is frequently vomiting, they are at risk of severe dehydration. Because their body cannot get the nutrients they need from food, it can lead to weight loss or poor weight gain. Please see your GP immediately if they are persistently vomiting.

Your doctor will do a physical examination of your baby’s abdomen. Sometimes the doctor can feel an olive-shaped lump, which is the enlarged pyloric muscles. Wave-like contractions might also be visible, often before a baby starts vomiting.

Your doctor might recommend blood tests to check for dehydration and/or electrolyte imbalance. They also might recommend an ultrasound to view the pylorus to confirm a diagnosis. Your baby may also need an x-ray if the ultrasound results aren’t clear.

What is the treatment for pyloric stenosis?

Your baby will be admitted to hospital for blood tests, and will most likely be treated for dehydration with the assistance of an intravenous drip to give them fluids. You will need to stop feeding while this is happening, so it could be a good idea to bring a pump.

Once your baby is rehydrated and their blood tests show improvements, an operation called a pyloromyotomy is necessary to correct the problem. This surgery is often minimally invasive. A slender viewing instrument is inserted through a small incision near the baby’s belly button, and the surgeon will cut only through the outside layer of the thickened pylorus muscle.

Recovery is usually quick, and the procedure only leaves a small scar. You will be able to resume feeding between 6-24 hours, and your baby will be discharged when they’re pain-free and tolerating full milk feeds. Then, you and your baby can get on with enjoying one another!