Diagnosis

Your child's doctor will:

• Gather a complete medical history. Your child's doctor will ask you about your child's past illnesses. He or she will also likely ask you about your child's diet and physical activity patterns.
• Conduct a physical exam. Your child's physical exam will likely include placing a gloved finger into your child's anus to check for abnormalities or the presence of impacted stool. Stool found in the rectum may be tested for blood.

More-extensive testing is usually reserved for only the most severe cases of constipation. If necessary, these tests may include:

• Abdominal X-ray. This standard X-ray test allows your child's doctor to see if there are any blockages in your child's abdomen.
• Anorectal manometry or motility test. In this test, a thin tube called a catheter is placed in the rectum to measure the coordination of the muscles your child uses to pass stool.
• Barium enema X-ray. In this test, the lining of the bowel is coated with a contrast dye (barium) so that the rectum, colon and sometimes part of the small intestine can be clearly seen on an X-ray.
• Rectal biopsy. In this test, a small sample of tissue is taken from the lining of the rectum to see if nerve cells are normal.
• Transit study or marker study. In this test, your child will swallow a capsule containing markers that show up on X-rays taken over several days. Your child's doctor will analyze the way the markers move through your child's digestive tract.
• Blood tests. Occasionally, blood tests are performed, such as a thyroid panel.