Pyloric Stenosis

What Is Pyloric Stenosis?
Pyloric stenosis is a narrowing of the pylorus, the lower part of the stomach through which food and other stomach contents pass to enter the small intestine. When an infant has pyloric stenosis, the muscles in the pylorus have become enlarged to the point where food is prevented from emptying out of the stomach.

Also called infantile hypertrophic pyloric stenosis or gastric outlet obstruction, pyloric stenosis is fairly common - it affects about three out of 1,000 babies in the United States. Pyloric stenosis is about four times more likely to occur in firstborn male infants. It has also been shown to run in families - if a parent had pyloric stenosis, then an infant has up to a 20% risk of developing the condition. Pyloric stenosis occurs more commonly in Caucasian infants than in babies of other ethnic backgrounds, and affected infants are more likely to have blood type B or O.

Most infants who develop pyloric stenosis are usually between 2 weeks and 2 months of age - symptoms usually appear during or after the third week of life. It is one of the more common causes of intestinal obstruction during infancy that requires surgery.

For more info: http://kidshealth.org/parent/medical/digestive/pyloric_stenosis.html