Projectile vomiting is when vomit flies out of a baby’s mouth forcefully. It will project like an arc several feet back, and looks quite different to the undramatic dribble of possetting. One important cause of projectile vomiting is pyloric stenosis, which occurs in young children. Pyloric stenosis is when there is a progressive thickening of the lower aspect of the stomach, causing a tightening or narrowing. This tightening means food can’t leave the stomach, causing an obstruction, and it requires immediate medical attention and treatment. The symptoms often occur in the first 5 weeks of life. It is more common in children whose parents had pyloric stenosis as a child, and in first-born males. The problem relates to the pylorus, a valve that opens and closes during digestion, so food can pass from the stomach to the small intestine and on through the bowel.
The first and main symptom is usually vomiting. It might look like posseting initially but gradually reveals itself to be projectile in nature, occurring shortly after feeds, or occasionally hours later. Because of increased vomiting, babies are often hungry and irritable and want to feed more often. Over time they will have difficulty gaining weight and may even lose weight quickly. Because less food is digested, they may also have fewer bowel movements. Another sign you may notice is their tummy is rippling or contracting after feeding. It's really important to look out for signs of dehydration in babies who are vomiting often.
The doctor will examine baby’s tummy (there may be a lump the size of an olive present), check their weight and the trend in weight gain, and look for any signs of dehydration. Sometimes blood tests are required to check the severity of dehydration. Pyloric stenosis is usually confirmed with an ultrasound of the tummy but on some occasions babies may be required to drink a chalky substance called barium and have X-rays taken to confirm the site of blockage.
If pyloric stenosis is confirmed, a surgery called a pyloromyotomy will need to be done. This involves cutting through the stomach thickening to release the pylorus, thereby clearing the obstruction and fixing the cause. After successful surgery, you will notice an immediate improvement in your baby and they shouldn’t need any further surgeries.
There are other causes of vomiting. If this is something that has happened over a short period then it could be a stomach bug. Diarrhoea may appear alongside, and this doesn’t occur with pyloric stenosis. Another cause could be reflux. Most babies don't have projectile vomiting with this, but they do have a lot of spit-up after feeding and they will cry and look uncomfortable. And finally, milk protein allergy can cause stomach contents to appear again, but this is never projectile in nature.