Utility of endoscopy in infantile hypertrophic pyloric stenosis.

Hypertrophic pyloric stenosis (HPS) is a common cause of non-bilious vomiting in infants. In USA, operation for HPS is one of the commonest surgical procedure performed on infants.1 Etiology remains poorly understood. A recent epidemiological survey from Sweden2 has noted a distinct difference in geographical distribution suggesting an environmental causation. A palpable pyloric 'tumor' is present in majority of the cases although in a recent US series3 this physical sign was noted in only 23% infants on diagnosis.