Hypertrophic pyloric stenosis (HPS) in infants 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 HPS, the muscles in the pylorus have enlarged resulting in narrowing within the pyloric channel preventing food from emptying out of the stomach.
HPS is a form of gastric outlet obstruction, which means a blockage from the stomach to the intestines. It affects three