What is anorectal manometry?

Anorectal manometry is a test that evaluates the pressure of the anal sphincter and the reactivity of the lower tract of the large intestine (also known as posterior rectal wall). Thus, this test is essentially testing how well the anal sphincter and rectum are working together.

It is quite helpful in the following cases:

• As a diagnostic exam for some large intestine disorders.
• To investigate those with faecal incontinence or constipation.

How does it work?

A small plastic tube (measuring around 0.5 cm) is inserted into the anus and passed through to the rectum a small way.

The tube can detect the pressure and the type of movements carried out by the anal muscles. After its insertion, a small balloon on the tip of the tube is inflated, in order to analyse the reactivity of the posterior rectal wall. All of the movements are recorded by a machine. The exam lasts 30 minutes and there is no need for any anaesthesia.

What is anorectal manometry for?

Anorectal manometry is not a primary diagnostic method as it is usually done after other tests (such as an X-ray scan or an endoscopy) to get further information and monitor the progression of some conditions, including:

• Constipation
• Difficulty in defecation
• Bowel incontinence or diarrhoea
• Anal spasms
• Rectal prolapse, anal fissures and haemorrhoids
• Complications after a surgery

How can I prepare for it?

You will need to empty your bowel before the procedure, which can be done by having an enema two to three hours beforehand. You will need to abstain from food the day of your manometry too. After the procedure, you may go home by yourself and resume normal activities.

What does it feel like during the test?

Anorectal manometry is not a painful test, but you may feel some slight discomfort, but it is a simple procedure with very low risk of complications.

What would a 'bad' result mean?

If the test showed there was a problem, you might have to undertake:

• Dietary changes
• Surgery
• Muscle strengthening exercises
• Medication