Pyloric stenosis

Alternative names:

congenital hypertrophic pyloric stenosis; gastric outlet obstruction; hypertrophic pyloric stenosis

Definition:

A narrowing of the outlet from the stomach to the small intestine (called the pylorus) that occurs in infants.

Causes, incidence, and risk factors:

In infants, this condition is caused by a thickening of the musculature of the pylorus, which stops the stomach from emptying into the duedenum and small intestine. The cause of the thickening is unknown, although genetic factors may play a role. It occurs more commonly in males than in females. Approximately 1 out of 4,000 infants is affected. Symptoms appear several weeks after birth.