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Hirschsprung's disease is a condition that affects the large intestine (colon or large bowel) and causes problems with passing stool. It's present when a baby is born (congenital) and results from missing nerve cells in the muscles of a portion of the baby's colon.

Children with Hirschsprung's disease can be constipated or have problems absorbing nutrients from food. In severe cases of Hirschsprung's disease, a newborn child experiences an obstructed colon and is unable to have a bowel movement. In mild cases, doctors may not detect the disease until later in a child's life.

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.

Signs and symptoms may vary with the severity of the condition. Sometimes they appear right after the baby is born. Other times they may not be apparent until the baby becomes a teenager or adult. In newborns, signs may include:

• Failure to pass stool within the first or second day of life
• Vomiting, including vomiting a green liquid called bile — a digestive fluid produced in the liver
• Constipation or gas, which may make a newborn fussy
• Diarrhea

In older children, signs can include:

• Swollen abdomen
• Lack of weight gain
• Problems absorbing nutrients, leading to weight loss, diarrhea or both and delayed or slowed growth
• Infections in the colon, especially in newborns or very young children, that may include enterocolitis, a serious infection with diarrhea, fever and vomiting and sometimes a dangerous expanding (dilation) of the colon

In older children or adults, signs may include chronic constipation and a low number of red blood cells (anemia) because blood is lost in the stool.

Normally, as a baby grows in the womb, bundles of nerve cells (ganglia) begin to form between the muscle layers along the length of the colon. This process begins at the top of the colon and ends at the bottom (rectum). In children with Hirschsprung's disease, this process does not finish and the ganglia do not form along the entire length of the colon. Sometimes the cells are missing from only a few centimeters of the colon. Other times a longer portion may be affected.

Why this happens is unknown. It may be associated with mutations in several genes. It may also be associated with multiple endocrine neoplasia, type IIB — a syndrome that causes noncancerous tumors in the mucous membranes and adrenal glands (located above the kidneys) and cancer of the thyroid gland (located at the base of the neck).

Hirschsprung's is not caused by anything that the mother does during pregnancy. In some cases, the disease may be inherited, even if neither parent has the disease. Hirschsprung's is also 10 times more likely to occur in children with Down syndrome.

Because Hirschsprung's disease can be inherited, if you have one child with the disease, your future children may also be at risk. The disease is also five times more common in males than in females.

To determine whether Hirschsprung's disease is present, your child's doctor may conduct a series of tests. This may include one or all of the following:

• Abdominal X-ray. If Hirschsprung's is present, as stool backs up in the colon, the X-ray may reveal decreased air in the colon or areas in which the colon has stretched wider than normal.

• Barium enema. This diagnostic test allows the doctor to evaluate the entire colon with an X-ray. Barium, a contrast dye, is placed into the bowel in an enema form. The barium fills and coats the lining of the bowel, creating a clear silhouette of the colon and rectum. Air may also be added to provide better contrast on the X-ray.

  In some cases, another liquid called diatrizoate ( Gastrografin, Gastroview, Hypaque) may be used instead of barium. This liquid may be used in newborns to help remove a hard first stool. It causes water to be pulled into the intestine, which softens the stool.

  The test typically takes about 20 minutes and can be somewhat uncomfortable because the contrast agent and air distend the bowel. There's also a slight risk of perforating the colon wall.

  In cases of Hirschsprung's disease, the areas of the colon missing the ganglia nerve cells can appear narrowed. A follow-up exam 24 hours later may show remaining barium in the colon. This problem passing the barium may also indicate Hirschsprung's disease.

• Manometry. This test is typically done on older children and adults. During the test, the doctor inflates a balloon inside the rectum. The anal muscle should relax as a result. If it doesn't, Hirschsprung's disease may be the cause.

• Biopsy. The doctor surgically removes a sample of tissue from the colon for study under a microscope. He or she looks for evidence of missing ganglia nerve cells, which would indicate Hirschsprung's disease.

  In rectal suction biopsy, the doctor removes some cells from the mucous lining of the colon by using a suction device. Because this doesn't involve cutting into the colon tissue, no anesthesia is necessary. If the biopsy shows that ganglia are present, Hirschsprung's disease is not diagnosed. If no ganglia cells are seen in the sample tissue, a full-thickness biopsy is needed to confirm Hirschsprung's disease.

  In full-thickness biopsy, more tissue from deeper layers of the colon is removed surgically or through rectal suction for study under the microscope. Absence of ganglia cells indicates Hirschsprung's disease.

Surgery is the only proven, effective treatment for Hirschsprung's disease. The procedure is called pull-through surgery and involves removing the section of the colon that has no ganglia cells, then connecting the remaining healthy end of the colon to the rectum.

Sometimes pull-through surgery is done in one step immediately after diagnosis. Other times, a doctor may choose to complete the process in two steps. First, the doctor will remove the abnormal portion of the colon and perform an ostomy. In these cases, after removing the section without the ganglia cells, the doctor may perform an ostomy. This involves creating a small hole (stoma) in the child's abdomen and connecting the top, healthy portion of the colon to the stoma. Stool then leaves the body through the stoma into a bag that attaches to it, allowing the lower part of the colon to heal. A stoma bag must be emptied several times a day. Ostomy may include:

• Illeostomy. In illeostomy, the doctor removes the entire colon and connects the small intestine to the stoma.
• Colostomy. In colostomy, the doctor leaves part of the large intestine and attaches this to the stoma.

Later, after allowing time for the child to recover from the first surgery, the doctor will close up the stoma and perform a second surgery to connect the healthy portion of the colon to the rectum.

Complications of surgery
After surgery, most children pass stool normally. Some may experience diarrhea initially, but after some time stool will become more solid. Toilet training may take longer because some children have difficulty coordinating the muscles used to pass stool. This improves with time in most children. Constipation may continue in some children, although laxatives should help. Eating high-fiber foods also can help with diarrhea and constipation.

A child is also at risk of developing enterocolitis in his or her colon or small intestine after surgery. Be aware of signs and symptoms of enterocolitis, and call the doctor immediately if any of these occur:

• Fever
• Swollen abdomen
• Vomiting
• Diarrhea
• Bleeding from the rectum
• Sluggishness

Most children with Hirschsprung's disease go on to live a normal life. However, because the colon absorbs much of the water and salt the body needs and a child's colon is shortened during surgery, he or she may not get all the fluids needed. You may need to ensure your child drinks more fluid.

Hirschsprung's disease can lead to malnutrition and weight loss, especially in very young children. Some children may need tube feedings at the doctor's office to get adequate nutrients. How long this is necessary varies on how severe the disease is, how old the child is when diagnosed and what types of complications, such as enterocolitis, have occurred.