Hypertrophic pyloric stenosis is a common condition in infants with 2 - 12 weeks of postnatal life. The cause of this disease remains obscure. Clinical diagnosis is based on the history of projectile, nonbilious vomiting, gastric hyperperistalsis and a palpable pyloric "tumor". The authors review the typical findings seen on upper gastrointestinal x-ray series and abdominal ultrasonography. The diagnostic criteria for hypertrophic pyloric stenosis are presented and the applications of these two methods are established on the basis of the current literature.
Hypertrophic pyloric stenosis; Pylorus; Vomiting; Ultrasonography; Infants