Anorectal Manometry

What Is Anorectal Manometry?

Anorectal manometry measures the pressures and coordination of the rectum and anal sphincter muscles during rest, squeeze, and simulated defecation.

The test evaluates how well the muscles and nerves involved in bowel movements are functioning and whether they are working together appropriately.

It is commonly used to help diagnose:

• Chronic constipation
• Fecal incontinence
• Pelvic floor dysfunction
• Obstructed defecation
• Dyschezia
• Post-surgical bowel dysfunction following rectal or colorectal procedures

Conditions Evaluated with Anorectal Manometry

Chronic Constipation

Difficulty passing stool or a sensation of incomplete evacuation may be related to impaired rectal sensation or dyssynergic defecation.

Fecal Incontinence

Inability to control bowel movements can result from sphincter weakness, impaired sensation, or coordination disorders.

Pelvic Floor Dysfunction

Anorectal manometry helps identify problems coordinating the muscles required for defecation.

Obstructed Defecation

Patients who feel stool cannot pass despite straining may benefit from pressure and coordination evaluation.

Dyschezia

Pain or excessive straining during bowel movements may reflect abnormal muscle function.

Post-Surgical Complications

Following rectal or colorectal surgery, anorectal manometry can assist in evaluating functional bowel outcomes.

What to Expect During the Procedure

Anorectal manometry is a brief, outpatient test that does not require sedation.

During the procedure:

• A thin, flexible catheter — thinner than a pencil — is lubricated and inserted approximately 4–5 inches into the rectum.
• The catheter contains a small balloon at the tip and additional small balloons positioned along its length.
• The catheter connects to a handheld device that measures rectal and anal sphincter pressures.
• The patient will be asked to squeeze, relax, and push at specific intervals.

After the examination, patients may drive themselves home and resume normal activities.
Blood thinners do not need to be held prior to the procedure.

Why Objective Functional Testing Matters

Symptoms such as constipation, incontinence, or obstructed defecation can have multiple underlying causes. Anorectal manometry provides objective data to clarify whether symptoms are due to:

• Sphincter weakness
• Impaired rectal sensation
• Dyssynergic defecation
• Pelvic floor coordination disorders

Accurate diagnosis supports targeted treatment recommendations and improves continuity of care.

Frequently Asked Questions About Anorectal Manometry