Anorectal Manometry &
Biofeedback Prep

What is anorectal manometry?

Anorectal manometry is a test performed to evaluate patients with constipation or fecal incontinence. 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.

What is biofeedback?

During anal manometry, special exercises of the pelvic muscles can strengthen the muscle, retrain the coordinated relaxation of the anal sphincter, and improve rectal sensation via sensory/visual conditioning techniques.

Why are these tests done?

These tests are done for pelvic floor problems like constipation and fecal incontinence.

Fecal incontinence: There are many causes of fecal incontinence. Weak anal sphincter muscles or poor sensation in the rectum can contribute to fecal incontinence. If these abnormalities are present, they can be treated. Biofeedback techniques using anal manometry and special exercises of the pelvic floor muscles can strengthen the muscles and improve sensation.

Constipation: There are many causes of constipation. Some involve sluggish movement through the whole colon, whereas others involve the anal sphincter muscles. In some patients with constipation, the anal sphincter muscles do not relax appropriately when bearing down or pushing to have a bowel movement. This abnormal muscle function may cause a functional type of obstruction. Muscles that do not relax with bearing down can be retrained with biofeedback techniques using anal manometry. 

How do you prepare for the procedure?

Give yourself one or two Fleet® enemas 2 hours prior to your study. You can purchase the Fleet enema from a pharmacy or supermarket.

You should not eat anything during the two hours prior to the procedure. If you are diabetic, this may involve adjusting your diabetic medications.

You may take regular medications with small sips of water at least 2 hours prior to the study.

If you have heart disease, kidney disease, or electrolyte abnormalities, contact your physician prior to beginning preparation with Fleet enemas.

What can I expect during the procedure?

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, take a brief health history, and answer any questions you may have. The patient then lies on his or her left side.

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 to assess the normal reflex pathways. 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. To squeeze, the patient tightens the sphincter muscles as if trying to prevent anything from coming out. To push or bear down, the patient strains down as if trying to have a bowel movement. One other test may also be done: Balloon expulsion test; a measurement of the time it takes to expel a balloon from the rectum.

What are possible complications of the test?

Minor rectal irritation or possible bleeding may occur, and if latex allergies are present, they need to be discussed beforehand.

What to expect after the test?

After the examination, you may drive yourself home and go about your normal activities.

You can make an appointment with your physician in 2 weeks to discuss the test results.