Pyloric stenosis

This factsheet is for parents of children with pyloric stenosis, or people who would like information about it.

Pyloric stenosis is a condition that develops in babies in the first few weeks after they are born. It means that part of the baby's digestive system has narrowed, so milk can't get out of the stomach to be digested.

About pyloric stenosis

The pylorus is the passage from the stomach into the small bowel. Pyloric stenosis is when the muscle in this area – called the pyloric sphincter – thickens, making the opening narrow. As a result of this narrowing, milk can't get out of the stomach to be digested.

Pyloric stenosis affects about one baby in every 400. The symptoms usually appear when your baby is around three weeks old, but can start any time between one and 18 weeks after birth.

Pyloric stenosis is more common in boys than in girls, particularly in firstborn babies.

Symptoms of pyloric stenosis

The first symptom you notice will probably be your baby vomiting small amounts of milk after feeding. At first, this may not be any more than usual, and may only occur after some feeds. However, the vomiting will become more severe and powerful, and start to happen after most feeds. This is called projectile vomiting and may be so forceful that it travels some distance out of your baby's mouth. The milk that your baby vomits may consist of curdled milk and, on occasion, may contain blood or have a similar colour and consistency to coffee grounds.

Other symptoms that your baby may have include:

• being hungry all the time
• constipation, with stools that look like ‘rabbit pellets’
• dry nappies due to not urinating often
• weight loss
• lack of energy
• yellowing of his or her skin (jaundice)

If your baby has these symptoms, see your GP. It's important that your baby receives treatment for pyloric stenosis, otherwise he or she may become seriously dehydrated. Your baby also won't be able to put on weight as he or she won't be absorbing any nutrients from the milk.

Causes of pyloric stenosis

Doctors don’t understand the exact reasons why some babies develop pyloric stenosis. However, there is evidence that the condition runs in families and is associated with conditions such as Turner’s Syndrome and disorders affecting the digestive system.

Diagnosis of pyloric stenosis

Your GP will ask about your baby's symptoms and examine him or her. During the examination, your doctor will feel to see if there is a small, hard lump on the right-hand side of your baby's stomach. This is called the 'olive test' because the thickened pylorus feels a bit like an olive.

Your GP may ask you to give your baby a ‘test feed’ so that he or she can feel your baby’s abdomen (tummy) and see any vomiting afterwards. During the feed, it may be possible to see the muscles around your baby's stomach moving from side to side as they try to push milk through the pylorus.

Your GP will want to rule out other conditions that could be causing your baby's symptoms, such as an infection, overfeeding or a milk allergy.

If your GP thinks your baby has pyloric stenosis, he or she will refer you to a specialist. The specialist may do more tests including:

• blood tests
• an ultrasound scan – this uses sound waves to produce an image of the inside of your baby's abdomen and will show the thickened pylorus muscle

Treatment of pyloric stenosis

Your baby will need to have an operation called a pyloromyotomy. This is sometimes referred to as a Ramstedt's pyloromyotomy or a Ramstedt operation. The surgeon will separate your baby's pylorus muscle and spread it open. This allows your baby's pylorus to widen so that milk can pass through.

Before the operation, your baby may be put on a drip for approximately 24 hours in order to rehydrate him or her.

The operation is carried out under general anaesthesia. This means that your baby will be asleep during the operation and will feel no pain. The operation takes about half an hour to an hour, depending on the type of operation used.

After the operation your baby will probably have to stay in hospital for a few days. Your baby’s surgeon will give you advice about feeding. He or she will probably tell you to wait a few hours before feeding to try to reduce the risk of vomiting, and then recommend small amounts of milk at first. Your baby may still vomit a bit to start, but this should improve within a week.

You will be able to take your baby home once he or she is feeding well and putting on weight. Almost all babies who have this operation recover well.

 

Produced by Kerry McKeagney, Bupa’s Health Information team, March 2012. 

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.