Digestive and Gastrointestinal Conditions

Pyloric Stenosis

What is pyloric stenosis?

Pyloric stenosis (pronounced pie-LOR-ik sten-OH-sis) is a thickening in the muscle at the end of the stomach called the pylorus. The enlarged muscle can block or slow the passage of food from the stomach to the intestine. This can cause symptoms such as vomiting, often in a forceful way (projectile vomiting).

Pyloric stenosis in children

Pyloric stenosis is a common problem for babies between 2 weeks and 3 months old. It affects about 1 in every 300 babies.

Pyloric Stenosis at Seattle Children’s

The experts you need are here

We treat many babies with pyloric stenosis. We take care of 40 to 60 children with this condition every year. Our surgeons are very experienced in doing the surgery that children with pyloric stenosis need to eat well and thrive.

Your child gets long-term care and support

When you come to Seattle Children’s, you have a team of people to care for your child before, during and after surgery. Along with your child’s surgeon, you are connected with gastroenterologists, nurses, dietitians, child life specialists, social workers and others. We work together to meet all of your child’s healthcare needs and help your family through this experience.

Symptoms of Pyloric Stenosis

All babies spit up or vomit from time to time. Babies with pyloric stenosis spit up more often – after most feedings – and they also vomit more often than usual. Vomiting is the main symptom of pyloric stenosis.

Over time, the problem gets worse: 

  • Your baby may spit up or vomit more often as time goes on.
  • Your baby may have projectile vomiting, which means milk or formula spurts out with great force and may travel several feet.
  • Eventually, your baby may not be able to keep down any milk or formula. 

Babies with pyloric stenosis usually don’t seem uncomfortable or sick except when they are vomiting. They may appear hungry soon after vomiting because they aren’t able to keep down or process their food. Sometimes vomiting makes the baby’s stomach hurt.

If your baby spits up often, they may not have enough fluid in their body, a condition called dehydration. This can be deadly. If your baby is dehydrated: 

  • Your baby may be sluggish and less active
  • The top of the baby’s head and the eyes may be sunken
  • Your baby may not urinate as often as usual 

If babies vomit often for a few days, they may have fewer stools (feces). They may start to lose weight.

Diagnosing Pyloric Stenosis

Babies with pyloric stenosis usually have a history of vomiting often and with force. Your baby’s doctor will ask you whether your baby has had symptoms of pyloric stenosis.

The doctor will examine your baby’s stomach to feel for the thickened muscle. Often, the muscle feels like a lump the shape and size of an olive.

  • The doctor may also ask for imaging tests to look at the muscle at the end of the stomach. This may help doctors find out whether your baby is vomiting for a reason other than pyloric stenosis. These imaging tests include: 

    • Ultrasound of the baby’s belly (abdomen). This is the most common test we do for pyloric stenosis.
    • Barium X-ray. If we need to do this test, your baby will swallow a chalky liquid that helps the digestive tract show up on the X-ray.
  • If the doctor thinks your baby may have pyloric stenosis, the baby will have blood tests to check the levels of electrolytes, such as sodium and potassium, in the blood. Frequent vomiting over a short time can cause an imbalance in electrolytes that must be fixed.

Treating Pyloric Stenosis

Treatment for pyloric stenosis is surgery. Doctors make a small cut (incision) in the thickened muscle. This opens the narrow passage so food can pass more easily out of the stomach. The surgery is called pyloromyotomy (pie-lor-oh-my-OTT-uh-mee).

  • Before the surgery, your baby will need blood tests to check for electrolyte imbalances caused by vomiting. Babies also need IV (intravenous) fluids to replace fluid lost from vomiting. To get enough fluid, your baby may need to stay in the hospital for a day or so before surgery.

  • This surgery can usually be done through a few small cuts (incisions), called laparoscopic surgery. Or the surgery can be done using an open technique, which usually uses 1 larger incision. Your baby’s surgeon will discuss this with you. In either method, surgeons usually make incisions near the belly button. Your baby’s surgeon can make the incision almost invisible.

    At the time of surgery, we give your child medicine (general anesthesia) to make them sleep without pain. The doctors at Seattle Children’s who give your child anesthesia are board certified in pediatric anesthesiology. They have extra years of training in how to take care of children.

    The surgeon makes a small incision over your baby’s stomach and looks at the pylorus muscle. Then the surgeon makes a small, length-wise cut in the pylorus muscle to spread out the thickened muscle. The surgeon does not cut the inner lining of the passage, only the muscle around it. No tissue is removed.

    The surgery takes 15 minutes to 1 hour. Your baby will be in the recovery room for another hour. Some babies take more time to wake from anesthesia. Their time in the operating room is often longer than the actual surgery time because they need time to wake up from anesthesia.

    After surgery, your baby will stay in the hospital for 1 to 2 days. During this time, your baby may still vomit a little as their body adjusts to the surgery. This is normal.

    We will give your baby pain medicine to make them comfortable. They will also continue to get IV fluids until they can take enough formula or breast milk by mouth.

    Your baby’s feeding will start slowly with watered-down formula at first. We will increase the amount and strength of feedings a little each time your baby eats. As soon as your baby can eat regular full-strength formula or breast milk and keep it down for several hours, they can go home.

  • At home, your baby will need slower feedings with more frequent burping for a few days. Then you can go back to your usual feeding routine.

    You’ll need to keep the incision clean and dry until it heals. The surgery team will teach you how to do this. Otherwise, you can care for your baby normally. There is no need to limit your baby’s activities.

    A surgery clinic nurse will call you 5 to 7 days after you go home from the hospital. If all is well, you do not need to return to the surgery clinic for a visit. If you or the nurse has any concerns about your child’s healing, we will set up a visit for you.

    Babies with pyloric stenosis are usually fine once they recover from surgery and are eating well. They’re at no greater risk than other children for stomach, intestine or other problems later on.

Contact Us

Contact our Pediatric General and Thoracic Surgery Department at 206-987-2794 for an appointment, second opinion or more information about pectus carinatum.

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