What is Anorectal Manometry (ARM)?
ARM is a test done to evaluate patients with constipation or fecal incontinence. The ARM uses technology to test nerve and muscle function. This test measures the pressures of the anal sphincter muscles, the sensation in the rectum, and the neural reflexes that are needed for bowel movements.
What is the preparation for an ARM?
You should not eat anything for the two hours before the procedure. You may take your regular medications with small sips of water prior to the procedure. Give yourself a Fleet® enema two hours before the ARM. The enema can be purchased from a pharmacy or supermarket.
What is the procedure for an ARM?
The ARM takes about 15-20 minutes. The ARM is a procedure that involves three short tests. An EMG test is performed first. The small sticky electrode patches will be placed near your anus. You will be asked to alternate between squeezing the pelvic muscles and bearing down two times.
For the second test, a small flexible catheter with a deflated “balloon” will be gently inserted into the rectum. You will be asked again to alternate between squeezing and resting.
In the third part of the test , ou will be describing a sensation of fullness (similar to that of needing to have a bowel movement) as the “balloon” at the end of the catheter is gently inflated. After the ARM, you may drive yourself home and go about your normal activities.
What can be learned from an ARM?
The anal and rectal area contains specialized muscles that are helpful to regulate proper passage of bowel movements. Normally, when stool enters the rectum, the anal sphincter muscle tightens to prevent passage of stool at an inconvenient time. If this muscle is weak or does not contract in a timely way, incontinence (leakage of stool) may occur. If the anal muscle does not relax when a person bears down to have a bowel movement, this could contribute to constipation. There are many causes of fecal incontinence. Weak anal muscles or poor sensation can be treated with pelvic floor muscle therapy or exercises. Some of these abnormal muscle functions contribute to constipation.
What are the risks of an ARM?
ARM is a safe, low risk procedure. Most patients describe little to no discomfort during the procedure. Complications are rare; it is possible that a perforation (tearing) or bleeding of the rectum could occur. Equipment failure is a remote possibility. If you are allergic to latex, you should inform us before the test so that a latex-free balloon can be used.