Skip to Content
Home > Wellness > Health Library > Pyloric Stenosis
Pyloric stenosis is a condition in which a baby's pylorus (the
connection between the stomach and the first part of the small intestine)
gradually swells and thickens, which interferes with food entering the
intestine. This causes the baby to vomit most or all of his or her
Vomiting caused by pyloric stenosis usually starts gradually and
gets worse over time. As the pylorus becomes tighter, the baby vomits more
frequently and more forcefully (projectile vomiting). As vomiting continues,
the baby will lose weight and become dehydrated.
Pyloric stenosis can occur any time between birth and 5 months of
age, but it most commonly develops about 3 weeks after birth. The start of
symptoms may be delayed if the baby was premature.
Pyloric stenosis is corrected with surgery (pyloromyotomy). After a
baby has the surgery, pyloric stenosis usually does not occur again.
Current as of:
August 21, 2015
John Pope, MD - Pediatrics & Brad W. Warner, MD - Pediatric Surgery
To learn more about Healthwise, visit Healthwise.org.
© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.