BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuPyloric stenosis in infantsCongenital hypertrophic pyloric stenosis; Infantile hypertrophic pyloric stenosis; Gastric outlet obstruction; Vomiting - pyloric stenosisPyloric stenosis is a narrowing of the opening from the stomach into the small intestine. This is called the pylorus. This article describes the condition in infants. Causes Normally, food passes easily from the stomach into the first part of the small intestine through a valve called the pylorus. With pyloric stenosis, the muscles of the pylorus are thickened. This prevents the stomach from emptying into the small intestine.The exact cause of the thickening is unknown. Genes may play a role, since children of parents who had pyloric stenosis are more likely to have this condition. Other risk factors include:Certain antibiotics Too much acid in the first part of the small intestine (duodenum) Certain diseases a baby is born with, such as diabetesPyloric stenosis occurs most often in infants younger than 6 months. It is more common in boys than in girls. Symptoms Vomiting is the first symptom in most children:Vomiting may occur after every feeding or only after some feedings. Vomiting usually starts around 3 weeks of age, but may start any time between 1 week and 5 months of age. Vomiting is forceful (projectile vomiting). The infant is hungry after vomiting and wants to feed again. Other symptoms appear several weeks after birth and may include:Abdominal pain Burping Constant hunger Dehydration (gets worse as vomiting gets worse) Failure to gain weight or weight loss Wave-like motion of the abdomen shortly after feeding and just before vomiting occurs Exams and Tests The condition is often diagnosed before the baby is 6 months old.A physical exam may reveal: Signs of dehydration, such as dry skin and mouth, less tearing when crying, and dry diapers Swollen belly Olive-shaped mass when feeling the upper belly, which is the abnormal pylorus Ultrasound of the abdomen may be the first imaging test. Other tests may include:Ultrasound of the abdomenAbdominal ultrasound is a type of imaging test. It is used to look at organs in the abdomen, including the liver, gallbladder, spleen, pancreas, and...ImageRead Article Now Book Mark Article Barium x-ray -- reveals a swollen stomach and narrowed pylorus Barium x-rayAn upper GI and small bowel series is a set of x-rays taken to examine the esophagus, stomach, and small intestine. Barium enema is a related test th...ImageRead Article Now Book Mark Article Blood tests -- often reveal an electrolyte imbalance ElectrolyteElectrolytes are minerals in your blood and other body fluids that carry an electric charge. Electrolytes affect how your body functions in many ways...Read Article Now Book Mark Article Treatment Treatment for pyloric stenosis involves surgery to widen the pylorus. The surgery is called pyloromyotomy.If it is not safe to put the infant to sleep for surgery, an endoscope is used. This is a long, flexible tube with a camera and a tiny balloon at the end. The balloon is inflated to widen the pylorus.EndoscopeAn endoscope is a medical device with a light attached. It is used to look inside a body cavity or organ. The scope is inserted through a natural o...Read Article Now Book Mark Article In infants who cannot have surgery, tube feeding or medicine to relax the pylorus is tried. Outlook (Prognosis) Surgery usually relieves all symptoms. As soon as several hours after surgery, the infant can start small, frequent feedings. Possible Complications If pyloric stenosis isn't treated, a baby won't get enough nutrition and fluid. The child can become underweight and dehydrated. When to Contact a Medical Professional Contact your health care provider if your baby has symptoms of this condition. Open ReferencesReferencesKliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM. Pyloric stenosis and other congenital anomalies of the stomach. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 355.Seifarth FG, Soldes OS. Congenital anomalies and surgical disorders of the stomach. In: Wyllie R, Hyams JS, Kay M, eds. Pediatric Gastrointestinal and Liver Disease. 6th ed. Philadelphia, PA: Elsevier; 2021:chap 25.AllVideoImagesTogDigestive system - illustration The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.Digestive systemillustrationPyloric stenosis - illustration A narrowing of the outlet from the stomach to the small intestine (called the pylorus) that occurs in infants.Pyloric stenosisillustrationInfantile pyloric stenosis - seriesPresentation Digestive system - illustration The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.Digestive systemillustrationPyloric stenosis - illustration A narrowing of the outlet from the stomach to the small intestine (called the pylorus) that occurs in infants.Pyloric stenosisillustration Infantile pyloric stenosis - seriesPresentation Related Information Review Date: 8/10/2021 Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.