Previously unsuspected infantile hypertrophic pyloric stenosis diagnosed by endoscopy.

Infantile hypertrophic pyloric stenosis is a common cause of upper gastrointestinal obstruction in infants and presents as projectile, nonbilious emesis in the first few weeks of life. In general, patients with infantile hypertrophic pyloric stenosis are diagnosed after a complete history and physical have been performed augmented by serum electrolyte evaluation, abdominal ultrasound, or upper gastrointestinal barium series. However, some patients can have equivocal radiographic testing and normal serum electrolytes. Two patients are presented in which esophagastroduodenoscopy was used to diagnose previously unsuspected infantile hypertrophic pyloric stenosis.