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 Hirschsprung disease can’t pass stool at all, which can result in the complete blockage of the intestines, a condition called intestinal obstruction. People with Hirschsprung disease are born with it and are usually diagnosed when they are infants. Less severe cases are sometimes diagnosed when a child is older. An Hirschsprung disease diagnosis in an adult is rare.

What are the large intestine, colon, rectum, and anus?

The large intestine, which includes the colon and rectum, is the last part of the digestive tract. The large intestine’s main job is to absorb water and hold stool. The rectum connects the colon to the anus. Stool passes out of the body through the anus. At birth, the large intestine is about 2 feet long. An adult’s large intestine is about 5 feet long.

Why does Hirschsprung’s disease cause constipation?

People with Hirschsprung disease have constipation because they lack nerve cells in a part or all of the large intestine. The nerve cells signal muscles in the large intestine to push stool toward the anus. Without a signal to push stool along, stool will remain in the large intestine.

In a healthy large intestine the nerve cells are found throughout the large intestine.

Short-segment Hirschsprung disease. Nerve cells are missing from the last segment of the large intestine.

Long-segment Hirschsprung disease. Nerve cells are missing from most or all of the large intestine and sometimes the last part of the small intestine.

How severe Hirschsprung disease is depends on how much of the large intestine is affected. Short-segment Hirschsprung disease means only the last part of the large intestine lacks nerve cells. Long-segment Hirschsprung disease means most or all of the large intestine, and sometimes the last part of the small intestine, lacks nerve cells.