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Anorectal Physiology

Patients either with symptoms relating to faecal incontinence, or constipation and difficulty in passing stools may need to undergo anorectal physiology testing.

This testing is relatively straightforward – requiring a Microlax enema before leaving home and no anaesthetic is needed. It is performed on an outpatient basis. The test, called 'anorectal manometry', involves measuring pressures inside the anus and rectum and to do this, small hollow tubes are placed into the anus. During the test, the way the anal muscles respond to the patient coughing, squeezing or straining will be measured.

Other tests may also be required, such as a 'pudendal nerve study' and/or a 'rectal balloon filling'.

Another common test is endoanal / endorectal ultrasound. This is used to detect/assess any rectal tumours or anal fistulas. It is also used to assess the function of the anal sphincter muscle. It involves the insertion of an ultrasound probe in the anus which enables detailed imagery of the anal and rectal wall to be captured. As with the anorectal physiology testing, endoanal ultrasound is carries out on an outpatient basis and required no preparation or anaesthetic. In some cases, the patient may need to have an enema before the test. The test normally takes 5-15 minutes to complete.