Abstract

Infants with hypertrophic pyloric stenosis born in Belfast during the 13 years 1957-1969 have been reviewed. Their distribution shows a bias towards higher social classes, breast feeding, and primogeniture. Obstetric factors and parental ages seem to be of no importance. More affected infants were born during winter months than would be expected. The overall incidence of infantile pyloric stenosis in this community has fallen during the period under review. Clinically, the patients started vomiting at a mean age of 22 days and it is recommended that the condition should not be called 'congenital'. The size of the tumour is mainly determined by the size of the patient, rather than by his age or duration of symptoms. Attention is drawn to the occurrence of haematemesis in 17-5% and melaena in 2-9% of infants. Jaundice occurred in 1-8% of patients in this series, and is attributed to the adverse effect of starvation on hepatic glucuronyl transferase activity. Other conditions noted in these patients included inguinal hernia, partial thoracic stomach, and phenylketonuria. Subsequent growth and development were in the anticipated range.