Your child's health care professional will ask many questions about the child's medical history, toilet training history, diet, lifestyle, habits, medications, and behaviors. A thorough physical examination will be done to assess the child's general health as well as the status of the colon, rectum, and anus. The health care professional may insert a gloved finger into the child's rectum to feel for stool and make sure the anal opening and rectum are of normal size and that the anal muscles are of normal strength.
In most cases, blood tests are not part of the evaluation of constipation and/or encopresis. In some cases, an X-ray of the child's abdomen or pelvis may be performed to determine how much stool is present in the colon and to assess if the colon and rectum are enlarged. Occasionally, a contrast barium enema is performed. This is a special type of X-ray in which a small tube is inserted into the child's rectum, and the colon is slowly filled with a radiopaque dye (barium or hypaque). X-rays are taken throughout the procedure to see if there are any areas of narrowing, twisting, or kinking in the lower intestine that might cause the child's symptoms.
In some cases, anorectal manometry may be performed. For this test, a small tube with several pressure sensors is inserted into the child's rectum. During the test, the doctor can determine how the child is using his or her abdominal, pelvic, and anal muscles during defecation. Many children who have chronic constipation and/or encopresis do not use their muscles in a coordinated fashion when trying to pass stools.
The main objective of manometry is to determine whether there is normal pressure within the anus. Manometry can also show whether the nerves controlling the anal sphincter, anus, and rectum are present and working by measuring reflexes in this area. Manometry can measure how far the rectum is distended and whether sensation in this area is normal. Abnormal contractions of the muscles in the pelvic floor can be documented by using manometry.
Anorectal manometry can also be helpful to rule out Hirschsprung's disease, a very rare cause of constipation without encopresis. If Hirschsprung's disease is being seriously considered as a cause of your child's encopresis, a biopsy of the rectum may be necessary. A biopsy is the removal of a very tiny piece of tissue for examination under a microscope. This is done to look for characteristic signs of Hirschsprung's disease in the tissues.