Definition of Hirschsprung's disease:

Hirschsprung's disease is a blockage of the large intestine due to improper muscle movement in the bowel. It is a congenital condition, which means it is present from birth.

Causes, incidence, and risk factors:

Muscle contractions in the gut help digested materials move through the intestine. This is called peristalsis. Nerves in between the muscle layers trigger the contractions.

In Hirschsprung's disease, the nerves are missing from a short or long part of the bowel. Areas without such nerves can not push material through. This causes a blockage. Intestinal contents build up behind the blockage, causing the bowel and abdomen to become swollen. If the condition is severe, the newborn may fail to pass meconium or stool, and the newborn may vomit.

Milder cases may not be diagnosed until a later age. In older children, the disease may be cause chronic constipation, abdominal swelling, and decreased growth.

Hirschsprung's disease causes about 25% of all newborn intestinal obstruction. It occurs five times more frequently in males than in females. Hirschsprung's disease is sometimes associated with other inherited or congenital conditions such as Down syndrome.