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 endeavour to maintain your dignity at all times. The tests are an important part of the investigation of your bowel condition and will help your doctors to decide the best treatment for your problem. When you arrive to have your tests, you will be asked a number of questions about how your bowel works and the problems that you have been having. The tests take about one hour to complete. You do not need to take any laxatives or enemas before these tests.
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.
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 the muscles in your back passage so that we can measure the strength of the muscles.
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.
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.
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.
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.