Diagnosis

Your child's doctor will perform an exam and ask questions about your child's bowel movements. He or she might recommend one or more of the following tests to diagnose or rule out Hirschsprung's disease:

• Removing a sample of colon tissue for testing (biopsy). This is the surest way to identify Hirschsprung's disease. A biopsy sample can be collected using a suction device, then examined under a microscope to determine whether nerve cells are missing.

• Abdominal X-ray using a contrast dye. Barium or another contrast dye is placed into the bowel through a special tube inserted in the rectum. The barium fills and coats the lining of the bowel, creating a clear silhouette of the colon and rectum.

  The X-ray will often show a clear contrast between the narrow section of bowel without nerves and the normal but often swollen section of bowel behind it.

• Measuring control of the muscles around the rectum (anal manometry). A manometry test is typically done on older children and adults. The doctor inflates a balloon inside the rectum. The surrounding muscle should relax as a result. If it doesn't, Hirschsprung's disease could be the cause.