Pyloric Stenosis - Topic Overview

What is pyloric stenosis?

Pyloric stenosis is a problem with a baby’s stomach that causes forceful vomiting. It happens when the baby's pylorus, which connects the stomach and the small intestine, swells and thickens. This can keep food from moving into the intestine.

A baby may get pyloric stenosis any time between birth and 5 months of age. It usually starts about 3 weeks after birth. If your baby was born early (premature), symptoms may start later.

See a picture of pyloric stenosis .

What causes pyloric stenosis?

Experts don't know what causes pyloric stenosis. It may be passed down through families.

What are the symptoms?

The main symptom of pyloric stenosis is throwing up (vomiting) all or most of feedings. Vomiting usually starts gradually. As the pylorus becomes tighter over time, your baby's vomiting will become more forceful. If your baby keeps vomiting, he or she can become dehydrated. If your baby's vomit is yellow or green, he or she may have a more serious problem than pyloric stenosis.

Call your doctor if your baby is vomiting yellow or green liquid or has signs of pyloric stenosis. A baby with pyloric stenosis:

Throws up formula or breast milk shortly after a feeding.
Has a swollen upper belly after a feeding.
Acts fussy and hungry, even right after being fed.
Has fewer wet diapers and fewer, harder stools.

How is pyloric stenosis diagnosed?

Your doctor will do a physical exam and ask you about your baby's symptoms. Your baby may need imaging tests, such as an upper gastrointestinal (UGI) series or an abdominal ultrasound. Your baby also may need blood tests to see if he or she is dehydrated.

How is it treated?

Pyloric stenosis is treated with surgery to widen the opening between the stomach and the small intestine. Your baby likely will be ready to go home within 2 days after surgery. Almost all babies recover completely. After surgery, your baby probably won't get pyloric stenosis again.

Frequently Asked Questions

Learning about pyloric stenosis:	What is pyloric stenosis? What causes it? What are the symptoms? Who gets pyloric stenosis? When should I call a doctor?
Being diagnosed:	How is it diagnosed?
Getting treatment:	How is pyloric stenosis treated?
Ongoing concerns:	Can it come back? What complications may happen after surgery?
Living with pyloric stenosis:	How do I care for my baby in the hospital? How do I care for my baby after surgery?

WebMD Medical Reference from Healthwise

Last Updated: December 21, 2007

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