Anorectal manometry (or ARM) is a diagnostic test, not a treatment or intervention. This test utilizes a catheter and a balloon to study the nerves and muscles of the anus and rectum. It tests pressures and sensations in the anus and rectum. It is used to evaluate patients with fecal incontinence or constipation.
During anorectal manometry a small, flexible tube, about the size of a thermometer, with a balloon at the end is inserted into the rectum. The catheter is connected to a machine that measures the pressure. During the test, the small balloon attached to the catheter may be inflated in the rectum. This test measures the pressures of the anal sphincter muscles, the sensation in the rectum, and the neural reflexes that are needed for normal bowel movements.
Preparation for the procedure include taking two enemas prior to the examination. Tell your doctor in advance of the procedure about all medications that you’re taking and about any allergies you have to medication. He or she will tell you whether or not you can continue to take your medication as usual before the examination.
The test takes approximately 30 minutes. You will be asked to change into a hospital gown. A technician or nurse will explain the procedure to you and answer any questions you may have. The patient then lies on his or her left side. The catheter is then inserted into the rectum and slowly withdrawn. The nurse or technician may also ask the person to squeeze, relax, and push at various times. The anal sphincter muscle pressures are measured during each of these maneuvers.
Anorectal manometry is a safe, low risk procedure and is unlikely to cause any pain. Complications are rare: it is possible that a perforation (tearing) or bleeding of the rectum could occur.