This information is approved and/or reviewed by U-M Health System providers but it is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your physician or make an appointment to be seen if you have questions or concerns about this information or your medical condition.| Complete disclaimer
Anorectal Manometry (ARM)
Anorectal manometry measures the tone in the anal sphincter and rectal muscles. This procedure can diagnose problems with defecation (moving your bowels) involving:
- Resting anal sphincter tone
- Releasing anal sphincter tone
- Squeezing anal sphincter tone
- Muscle coordination
- Expulsion of materials
- Sensation of the rectum
Who needs anorectal manometry?
Patients who suffer from constipation or incontinence may be asked to have this procedure.
How is the procedure performed?
You will be asked to undress from the waist down and wear a patient gown with the opening in the back. A trained technologist will be conducting the test and will explain everything that will happen. The technologist will ask you to lie on an exam table, turn to your left side, and bend your knees. During the procedure a small plastic tube (with a small balloon at the end) will be inserted into your rectum after you are positioned on your side. The balloon will be inflated and measurements will be taken while you squeeze and relax your muscles. You will then be asked to expel the balloon on a commode. This test is performed in the GI Physiology Laboratory in the Medical Procedures Unit. The appointment may take up to one hour.
Will my insurance cover this procedure?
Please consult with your ordering physician and health insurance company to insure coverage. NOT ALL INSURANCE COMPANIES COVER THE COST(S) FOR THIS TEST. IF WE DO NOT HAVE INSURANCE AUTHORIZATION PRIOR TO THE TEST, YOU WILL BE RESPONSIBLE FOR PAYMENT.
How do I prepare for this procedure?
One and a half hours (90 minutes) before leaving home, you'll need to take two 500 cc warm tap water enemas. You may purchase the enema bag at a pharmacy or medical supply store. The enema usually takes 15 minutes to work but can take up to an hour. Fill the enema bag with 500 cc of warm tap water. (Not hot water). You will need to hang the enema bag on a nail or hook or have someone hold it to raise it about 12-18 inches above the rectum. Lying on your left side with your knees bent toward the chest; remove the cap from the enema tip. Gently insert the enema tip about 3-4 inches. Open the clamp and allow the water to flow slowly into your rectum. The water rate can be adjusted by moving the clamp. Retain the fluid as long as possible - at least 15 minutes - then expel. Take the second enema after you have expelled the first one.
How do I get my results?
Your physician will most likely prefer to correlate these results with other diagnostic tests. A return visit at a future date may be scheduled to discuss your results.
If you are unable to keep your appointment or you have questions regarding this test or medications, please call the GI Physiology Lab in the MPU at 734-936-9250, option 1.
U-M Health System Related Sites:
Department of Internal Medicine Division of Gastroenterology
Directions to the Medical Procedures Unit
Instructions for Patients with Diabetes Having Outpatient Tests (on insulin)
Instructions for Patients with Diabetes Having Outpatient Tests (no insulin)
Information provided by the Michigan Bowel Control Program, March, 2008.