Hirschsprung's Disease

Hirschsprung's disease, or HD, is a disease of the large intestine (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.

If HD is not treated, stool can fill up the large intestine. This can cause serious problems like infection, bursting of the colon, and even death.

Symptoms

Symptoms of HD usually show up in very young children. But sometimes they don't appear until the person is a teenager or an adult. The symptoms are a little different for different ages.

Symptoms in Newborns

Newborns with HD don't have their first bowel movement when they should. These babies may also throw up a green liquid called bile after eating and their abdomens may swell. Discomfort from gas or constipation might make them fussy. Sometimes, babies with HD develop infections in their intestines.

Symptoms in Young Children

Most children with HD have always had severe problems with constipation. Some also have more diarrhea than usual. Children with HD might also have anemia, a shortage of red blood cells, because blood is lost in the stool. Also, many babies with HD grow and develop more slowly than they should.

Symptoms in Teenagers and Adults

Like younger children, teenagers and adults with HD usually have had severe constipation all their lives. They might also have anemia.

Diagnosis

To find out if a person has HD, the doctor will do one or more of the following tests:

Barium Enema X Ray

For a barium enema x ray, the doctor puts barium through the anus into the intestine before taking the x ray picture. Barium is a liquid that makes the intestine show up better on the x ray.

In some cases, instead of barium another liquid, called Gastrografin, may be used. Gastrografin is also sometimes used in newborns to help remove a hard first stool. Gastrografin causes water to be pulled into the intestine, and the extra water softens the stool.

In places where the nerve cells are missing, the intestine looks too narrow. If a narrow large intestine shows on the x ray, the doctor knows HD might be the problem. More tests will help the doctor know for sure.

Manometry

The doctor inflates a small balloon inside the rectum. Normally, the anal muscle will relax. If it doesn't, HD may be the problem. This test is most often done in older children and adults.

Biopsy

This is the most accurate test for HD. The doctor removes and looks at a tiny piece of the intestine under a microscope. If the nerve cells are missing, HD is the problem.

Causes

HD develops before a child is born. Normally, nerve cells grow in the baby's intestine soon after the baby begins to grow in the womb. These nerve cells grow down from the top of the intestine all the way to the anus. With HD, the nerve cells stop growing before they reach the end.

No one knows why the nerve cells stop growing. But we do know that it's not the mother's fault. HD isn't caused by anything the mother did while she was pregnant.

Some children with HD have other health problems, such as Down's syndrome and other rare disorders. 

Why does HD cause constipation?

Normally, muscles in the intestine push stool to the anus, where stool leaves the body. Special nerve cells in the intestine, called ganglion cells, make the muscles push. A person with HD does not have these nerve cells in the last part of the large intestine.

Healthy large intestine: Nerve cells are found throughout the intestine.	HD large intestine: Nerve cells are missing from the last part of the intestine.

In a person with HD, the healthy muscles of the intestine push the stool until it reaches the part without the nerve cells. At this point, the stool stops moving. New stool then begins to stack up behind it.

Sometimes the ganglion cells are missing from the whole large intestine and even parts of the small intestine before it. When the diseased section reaches to or includes the small intestine, it is called long-segment disease. When the diseased section includes only part of the large intestine, it is called short-segment disease.

Reference:

National Digestive Diseases Information Clearinghouse, USA.