In 1717, Blair first described pyloric stenosis based on autopsy findings. It was not until 1887 that Hirschsprung described the clinical picture and pathology of pyloric stenosis. Ninety years later, Teele and Smith described the use of ultrasonography to diagnosis pyloric stenosis. Traditionally, this diagnosis has been based on the clinical findings of projectile nonbilious vomiting, the palpation of a pyloric tumour (or “olive”), and the presence of classic metabolic disturbances. Currently, ultrasonography is regarded as the diagnostic test of choice for an infant presenting with nonbilious emesis in which an “olive” is not palpated.
