Pyloric Stenosis

Pyloric stenosis (or infantile hypertrophic pyloric stenosis) is a condition that causes severe projectile non-bilious vomiting in the first few months of life. There is narrowing (stenosis) of the opening from the stomach to the first part of the small intestine known as the duodenum, due to enlargement (hypertrophy) of the muscle surrounding this opening (the pylorus, meaning "gate"), which spasms when the stomach empties. This hypertrophy is felt classically as an olive-shaped mass in the middle upper part or right upper quadrant of the infant's abdomen. In pyloric stenosis, it is uncertain whether there is a real congenital narrowing or whether there is a functional hypertrophy of the pyloric sphincter muscle. This condition typically develops in male babies in the first 2–6 weeks of life.

Pyloric stenosis also occurs in adults where the cause is usually a narrowed pylorus due to scarring from chronic peptic ulceration. This is a different condition from the infantile form.

Read more about Pyloric Stenosis:  Signs and Symptoms, Diagnosis, Pathophysiology, Treatment, Epidemiology