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Pediatric Pyloric Stenosis Clinical Presentation

  • Author: Jagvir Singh, MD; Chief Editor: Kirsten A Bechtel, MD  more...
Updated: Jul 27, 2015


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  • Classically, the infant with pyloric stenosis has nonbilious vomiting or regurgitation, which may become projectile (in as many as 70% of cases), after which the infant is still hungry.[10]
  • Emesis may be intermittent or occur after each feeding.
  • The emesis may become brown or coffee color due to blood secondary to gastritis or a Mallory-Weiss tear at the gastroesophageal junction.
  • The infant begins to show signs of dehydration and malnutrition, such as poor weight gain, weight loss, marasmus, decreased urinary output, lethargy, and shock.
  • The infant may develop jaundice, which is corrected upon correction of the disease.


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  • In as many as 60-80% of the infants with infantile hypertrophic pyloric stenosis (IHPS), a firm, nontender, and mobile hard pylorus that is 1-2 cm in diameter, described as an "olive," may be present in the right upper quadrant at the lateral edge of the rectus abdominus muscle. This is best palpated after the infant has vomited and when calm, or when the gastric contents have been removed via nasogastric tube.
  • Clinicians may also observe gastric peristalsis just prior to emesis as the peristaltic waves try to overcome the obstruction.
  • Signs of dehydration include depressed fontanelles, dry mucous membranes, decreased tearing, poor skin turgor, and lethargy.
  • The classic signs of infantile hypertrophic pyloric stenosis are becoming less common. The mean age of presentation is getting significantly younger, and infants are not developing the physical signs or electrolyte abnormalities they were 20 years ago. Additionally, the availability of diagnostic imaging is allowing clinicians to make this diagnosis before other clinical manifestations appear.


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  • The etiology of infantile hypertrophic pyloric stenosis is unknown and is probably multifactorial.
Contributor Information and Disclosures

Jagvir Singh, MD Director, Division of Pediatric Emergency Medicine, Lutheran General Hospital of Park Ridge

Jagvir Singh, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.


Richard H Sinert, DO Professor of Emergency Medicine, Clinical Assistant Professor of Medicine, Research Director, State University of New York College of Medicine; Consulting Staff, Vice-Chair in Charge of Research, Department of Emergency Medicine, Kings County Hospital Center

Richard H Sinert, DO is a member of the following medical societies: American College of Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Grace M Young, MD Associate Professor, Department of Pediatrics, University of Maryland Medical Center

Grace M Young, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Emergency Physicians

Disclosure: Nothing to disclose.

Chief Editor

Kirsten A Bechtel, MD Associate Professor of Pediatrics, Section of Pediatric Emergency Medicine, Yale University School of Medicine; Co-Director, Injury Free Coalition for Kids, Yale-New Haven Children's Hospital

Kirsten A Bechtel, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Additional Contributors

Garry Wilkes, MBBS, FACEM Director of Clinical Training (Simulation), Fiona Stanley Hospital; Clinical Associate Professor, University of Western Australia; Adjunct Associate Professor, Edith Cowan University, Western Australia

Disclosure: Nothing to disclose.


Dara A Kass, MD Clinical Assistant Instructor, Department of Emergency Medicine, State University of New York Downstate Medical Center, Kings County Hospital

Dara A Kass, MD is a member of the following medical societies: American College of Emergency Physicians, Emergency Medicine Residents Association, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

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Lateral view from an upper GI study demonstrates the double-track sign.
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