High Resolution Anorectal Manometry
High resolution anorectal manometry is a test used to evaluate the function and coordination of the sphincter and pelvic floor muscles of the anorectal anatomy. This study also assesses the measurement of resting and squeeze pressures, as well as the length of the anal canal. Anorectal manometry may be performed to test for conditions such as chronic constipation, fecal incontinence (inability to control bowel movements), rectal prolapse (condition where the rectum protrudes from the anus), or Hirschprung’s disease (congenital condition where the nerves in the wall of the colon are missing). This test may also be used in preoperative evaluations to assess sphincter function prior to rectal or anal surgery. In addition, anorectal manometry may be used in conjunction with biofeedback training, which can be an effective treatment and technique using anal manometry and special exercises to strengthen the anal muscle.
How Anorectal Manometry is Performed
A technician or nurse will perform this test after explaining the procedure to you. You will change into a hospital gown and be asked to lie on your left side with your hips and knees flexed. Since you will need to squeeze and relax during the procedure, you will not be sedated. A small, well-lubricated catheter or probe is inserted into your rectum. The catheter or probe is connected to a monitor that measures the pressures of several muscles in your rectum. During the study, a small balloon at the tip of the catheter or probe will be inflated to assess the normal reflex pathways. You will be asked to squeeze, relax, and push at various times, allowing the technician to measure the anal sphincter muscle pressure.
Preparation for Anorectal Manometry
Before your test day, your healthcare provider will obtain a history and answer any questions or concerns you might have. On the day of testing, you will need to perform two fleet enemas two hours prior to your arrival for the test. Tell your doctor in advance about any medications you take as you might need to adjust or withhold certain medications prior to this procedure. You will be asked to empty your bladder prior to the procedure. An additional enema may be performed if the home enema cleansing you performed is not sufficient.