Ano-Rectal Tests

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For many people the thought of having tests on their back passage can be very embarrassing and frightening. These tests are not painful and are carried out by professional staff who will try to maintain your dignity at all times. The tests are an import part of the investigation of your bowel condition and will help your doctors to decide the best treatment for your problem.

1. Ano-Rectal Physiology
This test is divided into two parts. You will be asked to lie on an examination couch on your left side with your knees bent.

a) Anal pressure measurement
This part of the test measures the strength of the muscles in your back passage. This involves introducing a small tube, about the size of a drinking straw, into your back passage. You will be asked to squeeze and relax your muscles in your back passage so that we can measure the strength of the muscles.

b) Rectal sensation and pressure measurements
The second part of the test assesses the amount that your rectum can hold. This involves passing another small tube with a balloon attached to it through the back passage. The balloon will be
inflated and you will be asked to say when you can feel that it is filling up. We will also measure the way the muscles relax using the same tube that was used for the first part of the test.

2. Pudendal Nerve Test
In some patients, tests on the nerves controlling the muscles of the back passage will be performed. To do this, a small electrode is passed into the rectum on the finger of a rubber glove. This
passes a very small electric current over the pelvic floor nerves which will cause the muscles in your back passage to twitch. This procedure can be a little uncomfortable, but is not painful.

3. Anal Sensation
This test is designed to investigate if there is any numbness in your back passage that might prevent you feeling your motions coming down. A tiny probe attached to a small battery is inserted into
your bottom and a small electric current is slowly increased until you can just feel it as a tingling sensation.

4. Endo-Anal Ultrasound
Ultrasound scans (pictures) of the muscles of your back passage are taken by passing a finger-sized probe into the anus. This is not painful, but may be a little uncomfortable. This test is used to
see any damage to the muscles of your back passage that may have occurred.

5. 24 Hour Anal Manometry
In some patients, prolonged investigation of the muscle function of the anus (back passage) and rectum is important. This test would first require a thin tube to be inserted through the back passage into the rectum. The tube would then be secured in place to the lower back and buttocks with elastic tape. You would then be required to dress, leaving only a connector attached to the other end of the tub coming out of your waistband.

The connector coupled to portable recording equipment (about the size of a Walkman) which you would wear with a strap over your shoulder. Recording would take place for 24 hours. During the night-time, you would simply remove the recording equipment from over your shoulder and place it under your pillow. This test will not prevent you from opening your bowels normally.

Further Information
Colorectal Nurse Specialist 01908 996953

This leaflet is based on one designed by the Association of Coloproctology of Great Britain and Ireland, but has been modified (with permission) by us to reflect local policies. The Association of
Coloproctology web site ( has further information on all aspects of colon and rectal disease.

People are unique and the alternatives, risks and benefits will of course vary from person to person. We hope this leaflet will support the information you have already received from your doctor in enabling you to make an informed decision.