20 May 2019
Ano-rectal Physiology Tests

Ano-rectal Physiology Tests


Anorectal physiology investigations are performed at the GI Physiology Unit on the Good Hope site, by specialist physiologists.


These tests assess the function and structure of the rectum and anal canal. They include:


  1. Anorectal Manometry – involving the insertion of a small thin catheter into the anorectum approx. 8cm. This takes measurements of muscle strength and responses, reflexes, sensitivity and co-ordination.
  2. Pudendal Nerve Studies – involving the insertion of a small electrode into the anorectum 5-6cm. This measures nerve activity.
  3. Endoanal Ultrasound – involving the insertion of a finger-sized ultrasound probe into the anoerctum 6-7cm. This provides 3-D images of the layers of the anal canal, from which measurements and assessment of integrity and thickness can be made.


Individually, or in combination, these tests are used to aid diagnosis and guide treatment for a range of bowel symptoms, including faecal incontineance, obstructed defaecation, constipation, anal fistula, anal fissure, anal pain. These tests may also be required as pre-assessment tools before certain types of surgery.


None of these tests require anaesthetic or any patient preparation, and all are usually painless.

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