Hirschsprung's Disease

Hirschsprung's disease is caused by an abnormality in nerve and muscle function. Muscle contractions in the normal gut help digested materials move through the intestine. This is called peristalsis. Nerves between the muscle layers trigger the contractions. In Hirschsprung's disease, the nerves (called ganglion cells) are missing from a short or long part of the bowel. Areas without these nerves cannot 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, a newborn child may fail to pass meconium (first stool) or stool, and the newborn may vomit. Hirschsprung's disease causes about 25 percent of all newborn intestinal obstructions.

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

Symptoms of Hirschsprung's disease include:

• Constipation
• Failure to pass a first stool (meconium) within 24 to 48 hours after birth
• Poor weight gain
• Swollen belly
• Vomiting

Diagnosis of Hirschsprung's Disease

Common exams for diagnosing Hirschsprung's disease include:

• Physical exam. During a physical examination, your child's pediatric gastroenterologist may be able to feel loops of bowel in the swollen belly.
• Rectal exam. By examining the child’s rectum, a pediatric gastroenterologist may find increased muscle tone in the rectal muscles.

Tests used to help diagnose Hirschsprung's disease include:

• Contrast barium X-ray. This test is usually done in newborns to visualize which part of the colon is affected. It is a type of fluoroscopy.
• Anorectal manometry. Anorectal manometry is used in older infants and children to measure pressure in the rectum. It is a type of motility test.
• Rectal biopsy. A rectal biopsy is used to analyze a rectal tissue sample to see if ganglion cells are present.