Pyloric Stenosis

Pyloric stenosis is a narrowing of the opening from the stomach to the first part of the small intestine, the pylorus. Symptoms include projectile vomiting without bile, most often after feeding, and typically become obvious at two to twelve weeks of age. The cause is unclear; risk factors in babies include birth by cesarean section, preterm birth, bottle feeding and being firstborn. It is diagnosed by feeling an olive-shaped mass in the abdomen, often confirmed by ultrasound. Treatment starts by correcting dehydration and electrolyte problems and is typically followed by surgery, first carried out in 1912 by Conrad Ramstedt. About one to two per 1,000 babies are affected, males about four times more often than females.