Pyloric Stenosis (also called Infantile Hypertrophic Pyloric Stenosis or Gastric Outlet Obstruction)

Condition Description

Pyloric stenosis is a condition where there is an obstruction in the gastrointestinal tract at the lower end of the stomach due to enlargement of the pyloric valve (also called the pylorus). The pyloric valve regulates emptying of stomach contents into the intestine, and for an unknown reason, in some babies it becomes enlarged during early weeks of life.

There are many theories about why this enlargement (hypertrophy) of the valve occurs, such as genetic predisposition, allergy, or hormonal effects. However, no specific causes have been proven. Typically, the babies begin to have forceful vomiting of their feedings in the second or third week of life. They will be very hungry right after vomiting. Persistent vomiting can quickly lead to dehydration and electrolyte imbalance, which can be life-threatening. Babies will fail to gain weight (or will lose weight). They may also become irritable and weak if this condition is not corrected. About 7% of babies will have other conditions such as intestinal malrotation, urinary tract obstruction, and esophageal atresia. However, over 90% of babies will have no other conditions. Babies who are quickly diagnosed and taken to surgery promptly will have an excellent outcome. They will be in hospital for 1-2 days post-operatively and will gradually resume their normal feedings. Pyloric stenosis occurs in 1 of every 200-300 live births and is four times more common in males. Our program has been tracking pyloric stenosis among live births in select counties since 2005 and are gradually expanding statewide.

• Using data from births to Hennepin and Ramsey county residents between 2010-2014, we found that 12.2 babies were born with pyloric stenosis per 10,000 births.
• Using this data, we estimate about 85 babies are born with pyloric stenosis every year in Minnesota.

Parental education and support are essential, and local, regional, and national organizations may be very helpful.

Condition specific organizations

• KidsHealth
• Medline