Hirschsprung disease (HD) is a disease of the large intestine that causes severe constipation or intestinal obstruction. Constipation means stool moves through the intestines slower than usual. Bowel movements occur less often than normal and stools are difficult to pass. Some children with HD can't pass stool at all, which can result in the complete blockage of the intestines, a condition called intestinal obstruction. People with HD are born with it and are usually diagnosed when they are infants. Less severe cases are sometimes diagnosed when a child is older. An HD diagnosis in an adult is rare. This publication by the National Institutes of Health (Publication No. 10-4384) provides information on the causes, symptoms and treatments of Hirschsprung disease.