Anorectal manometry is a test used to evaluate patients with constipation or fecal incontinence. This test measures the strength of the anal sphincter muscles, the sensation of the nerves in the rectum, and the reflexes that are needed to have a normal bowel movement.
Normally, when stool enters the rectum, nerves sense the stool and cause the anal sphincter muscles to tighten. This allows you to hold stool until you are ready to have a bowel movement. However, if the sphincter muscles are weak, leakage of stool can occur.
When you bear down to have a bowel movement, the same muscles should relax to allow the stool to pass from the rectum. In some cases, the sphincter muscles may tighten during a bowel movement, preventing evacuation. This can contribute to constipation. Also, if the nerves do not function properly, the sensation, or urge to defecate, may be altered.
- You may take your normal morning medications with small sips of water
- Do not eat or drink within two hours of your test.
- Two hours prior to your procedure, use one Fleet’s enema (purchase this over the counter at your nearest pharmacy or supermarket)
What To Expect
The test will take approximately 30 minutes. After changing into a gown a nurse will instruct you during each step of the procedure. You will lie comfortably on your left side and a small catheter will be inserted into your rectum to allow for pressure and sensation measurements. You will be asked to contract or release your rectal muscles during parts of the test. A small balloon on the tip of the catheter will be inflated in order to test your nerve sensation. You may experience a feeling of fullness or distention.
No sedation is needed. You will be able to drive yourself home and return to your normal activities immediately after the procedure.
There are no specific risks of anorectal manometry. Minor bleeding or discomfort are unusual, but could occur. Equipment failure or malfunction is a remote possibility.