Patient education: Anorectal manometry (The Basics)

What is anorectal manometry? — 

This is a test to measure the pressure inside different parts of the rectum and anus under different conditions. It also measures pelvic floor muscle function. The anus and rectum connect the colon (also called the large intestine) to the outside of the body (figure 1).

Anorectal manometry can also be used to learn if a person has normal sensations and reflexes in their rectum and anus. These are needed to have a normal bowel movement.

Why might I have anorectal manometry? — 

Your doctor might recommend this test to learn more about:

●Fecal incontinence – This is when a person loses control of their bowels. For example, they might leak solid or liquid bowel movements into their underwear or have a bowel movement while asleep.

●Constipation – This is a problem that makes it hard to have bowel movements. Bowel movements might be too hard, too small, difficult to get out, or happening fewer than 3 times a week.

●Other problems with the nerves or muscles around the anus and rectum, such as pain with having a bowel movement

Manometry can help the doctor find out if the muscles that control bowel movements are working right.

How do I prepare for anorectal manometry? — 

Your doctor or nurse will tell you if you need to do anything special to prepare.

Before the procedure, your doctor will ask about your "health history." This involves asking about any health problems you have or had in the past, past surgeries, and any medicines you take. Tell them about:

●Any medicines you are taking – This includes prescription and "over-the-counter" medicines, plus any herbal supplements. It helps to write down and bring a list of your medicines, or bring a bag with all your medicines with you.

●Any allergies you have

●Any bleeding problems you have – Certain medicines, including some herbs and supplements, can increase the risk of bleeding. Some health conditions also increase this risk.

Your doctor will also do a rectal exam. This means they look at the outside of your anus. They also use a lubricated finger to feel inside the opening.

You will also get information about:

●Eating and drinking before the procedure – You might need to "fast" before the procedure. This means not eating or drinking anything for a period of time. Or you might be allowed to have liquids until a short time before the procedure.

●If you need to use an enema to clean out your rectum before the procedure

Ask the doctor or nurse if you have questions or if there is anything you do not understand.

What happens during anorectal manometry? — 

Anorectal manometry is usually done by a nurse or technician with special training.

When it is time for the procedure:

●You will lie on your side. The nurse or technician will insert a small, lubricated tube through your anus and into your rectum. The tube has a balloon on the end.

●When the tube is in the right place, the nurse or technician will inflate the balloon. You might feel some pressure or fullness, but it should not hurt.

●A machine attached to the tube will measure the pressure in the area. This shows the nurse or technician how well these muscles are working.

●They might ask you to do certain things, like squeeze or relax your muscles in the area, or cough or bear down like you are having a bowel movement. They might ask if it feels like you need to have a bowel movement. After the test, they will remove the tube and balloon.

●In some cases, the nurse or technician might insert a small balloon into your rectum and fill it with water. Then, they will ask you to push the balloon out, as if you are having a bowel movement. They will time how long it takes you to push the balloon out of your rectum.

●Anorectal manometry usually takes about 30 minutes.

What happens after anorectal manometry? — 

You can go home and return to your normal activities.

Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your test shows any abnormal results, your doctor or nurse will talk to you about what to do next. In many cases, they might have you work with a physical therapist (exercise expert) for "pelvic floor muscle training." This involves learning exercises to strengthen and relax your pelvic muscles.

What are the risks of anorectal manometry? — 

Anorectal manometry is safe. There are small risks of:

●Discomfort during the procedure

●A small amount of bleeding from the rectum

What else should I know? — 

Before you go home, make sure you know what problems to look out for and when to call the doctor. Make sure you understand your doctor's or nurse's instructions. Ask questions about anything you do not understand.

More on this topic

Patient education: Fecal incontinence in adults (The Basics)
Patient education: Fecal incontinence in children (The Basics)
Patient education: Constipation in adults (The Basics)
Patient education: Constipation in children (The Basics)
Patient education: Pelvic floor muscle exercises (The Basics)

Patient education: Fecal incontinence (Beyond the Basics)
Patient education: Constipation in adults (Beyond the Basics)
Patient education: Constipation in infants and children (Beyond the Basics)
Patient education: Pelvic floor muscle exercises (Beyond the Basics)