Hirschsprung's disease usually is suspected based on symptoms and a physical exam. During the physical exam, your health professional will check your child's abdomen for bloating and excessive stool in the intestines and rectum.

If Hirschsprung's disease is suspected, the following tests may be done:

• Rectal biopsy. This is the most useful test for diagnosing Hirschsprung's disease. For this test, a small piece of rectal tissue is removed and examined under a microscope for the presence of nerve cells. If nerve cells are not present, Hirschsprung's disease is diagnosed.
• Barium enema. In this test, a whitish liquid (barium) is inserted through the rectum into the intestines. The barium coats the intestine to make it visible on an X-ray. If Hirschsprung's disease is present, the X-ray will show a swollen portion of the intestine followed by a narrowed area. However, a barium enema may not reveal signs of Hirschsprung’s disease if a child is younger than 3 months of age or if only a small part of the intestine is affected. A barium enema is not done if the doctor suspects that the large intestine has swollen to many times its normal size (toxic megacolon).
• X-ray of the abdomen. This test provides a picture of structures and organs in the abdomen, including the intestines.
• Anorectal manometry. In this test, a small tube is inserted into the rectum to measure how well the muscles in the anus are working. If the muscles do not relax, it may indicate Hirschsprung’s disease. In newborns (younger than 1 month) and babies born early, this test may not be accurate.² Also, a false-positive test result may be obtained if the large intestine is stretched for another reason, or if the child cannot or does not cooperate with the testing.

A delay in diagnosing Hirschsprung's disease can lead to a child developing serious, life-threatening complications.