Care at Children's

Pyloric stenosis is a condition that develops in newborns, from birth to about two months of age. The "pyloric muscle" is the muscular wall in the last part of the stomach, just before it empties into the small intestine. This muscular wall can thicken so much that the stomach can no longer empty. Vomiting occurs that can become so forceful that it is called "projectile vomiting”. The baby becomes progressively dehydrated. Urine output decreases, with fewer wet diapers. The baby loses weight and blood chemistries (electrolytes) become abnormal (low potassium, low chloride, "metabolic alkalosis").

Treatment begins with correction of dehydration and blood chemistry abnormalities using intravenous (IV) fluids. The diagnosis is confirmed by using ultrasound. Sometimes a traditional infant "upper gi" X-ray is performed as well. 

Once diagnosis is confirmed, and the dehydration and blood chemistries are corrected, pediatric surgeons at Penn State Children’s Hospital perform a "plyoromyotomy" operation to correct the problem. The "pyloromyotomy" operation is usually performed using laparoscopy (" surgery" / "video-endoscopic surgery") using only tiny "poke-holes" into the  abdomen rather than a traditional incision.

Most infants feed soon after surgery and are discharged within a day or two. There may be some vomiting after surgery, but usually very little.

Pyloric stenosis should only be treated by pediatric surgeons at a children’s hospital.

Groups, Classes & Support

Support groups provide an opportunity to share your feelings and connect with other parents and caregivers who are experiencing similar struggles.

Learn more about support groups offered at Penn State Health Milton S. Hershey Medical Center

Research & Clinical Trials

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Symptoms, Diagnosis & Outlook


Babies with pyloric stenosis may have symptoms, such as:

  • Vomiting, often projectile in the first 3 to 6 weeks of life. Vomiting may come and go or may happen after each feeding
  • Always hungry
  • Weight loss
  • Dehydration
  • Lethargy
  • Few or no bowel movements
  • Jaundice, yellowing of the skin and eyes

Causes & Risk Factors

No one knows what causes pyloric stenosis. Medication, including antibiotics, hormones, and growth factors have all been associated with pyloric stenosis. Genetics may also play a role.

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