Information on Hirschsprung's Disease

Hirschsprung's (HURSH-sprungz) disease, or HD, is a disease of the large intestine.The large intestine is also sometimes called the colon. The word bowel can refer to the large and small intestines. HD usually occurs in children. It causes constipation, which means that bowel movements are difficult. Some children with HD can't have bowel movements at all.

The stool creates a blockage in the intestine. Hirschsprung’s disease is a congenital disorder of the colon in which certain nerve cells, known as ganglion cells, are absent, causing chronic constipation (Worman and Ganiats 487). A barium enema is the mainstay of diagnosis of Hirschsprung’s, though a rectal biopsy showing the lack of ganglion cells is the only certain method of diagnosis.

Hirschsprung's disease occurs in one in every 5,000 babies born and is responsible for one-fourth of intestinal obstructions in newborns. It's five times more common in boys and sometimes occurs with other congenital conditions such as Down syndrome. Surgical removal of the diseased portion of the colon is the only treatment for Hirschsprung's disease.

The main symptom of Hirschsprung’s disease is constipation, which cannot be treated using laxatives or softeners. This occurs because faeces are pushed through the bowel until they reach the affected part. As this part of the bowel cannot squeeze rhythmically to push the faeces through the bowel, the faeces cannot move any further. As more food is digested and turned into faeces, the bowel becomes blocked causing discomfort and a swollen abdomen. Often babies with Hirschsprung’s disease do not pass meconium - the dark faeces passed in the first two days of life. Other symptoms include a swollen abdomen and vomiting green bile.

Eighty percent of children with Hirschsprung's disease show symptoms in the first 6 weeks of life. Children who only have a short segment of intestine that lacks normal nerve cells may not show symptoms for several months or years. The following are the most common symptoms of Hirschsprung's disease. However, each individual may experience symptoms differently.

Between the 5th and the 12th weeks of pregnancy, while the fetus is growing and developing, nerve cells form in the digestive tract, beginning in the mouth and finishing in the anus. For unknown reasons, the nerve cells do not grow past a certain point in the intestine in babies with Hirschsprung's disease. Scientists are not sure why the intestinal nerve cells do not form completely. Nothing has been shown to cause this problem, including medications a mother takes while pregnant or what a mother eats during pregnancy.

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.

In patients with Hirschsprung disease, ganglion cells are absent, leading to a marked increase in extrinsic intestinal innervation. The innervation of both the cholinergic and adrenergic systems is 2-3 times that of normal innervation. The adrenergic (excitatory) system is thought to predominate over the cholinergic (inhibitory) system, leading to an increase in smooth muscle tone. With the loss of the intrinsic enteric inhibitory nerves, the increased tone is unopposed and leads to an imbalance of smooth muscle contractility, uncoordinated peristalsis, and a functional obstruction.