Date issued: December 2021
For review: December 2023
Ref: B-326/AC/Colorectal/anorectal Physiology Tests v5
Anorectal Physiology Tests
You have been referred by your Consultant for anorectal physiology. These tests are to assess the function of your anus and back passage (rectum). The tests themselves will take approximately 20 minutes in total.
When are these tests performed?
These investigations are basic tests of the pelvic floor structure and function. We will request them for many patients with incontinence or difficulty in emptying the rectum and prolapse. We will also perform these tests in patients with other conditions affecting the bottom including anal fistulas and fissures or patients who have sustained a third or fourth degree tear following delivery of their baby.
On arriving in the department, you will be greeted and may be required to complete a questionnaire. Your appointment is with the Pelvic Floor Nurse or Consultant who will give you the opportunity to discuss the problems you may be having with your bowel control. You will be asked many questions, please answer as frankly as you can. Naturally many patients are anxious about undergoing these types of investigations and we try our very best to lighten the situation.
Test 1 – Digital Rectal Examination
Is the internal examination of the back passage (rectum). This involves putting a gloved finger in the back passage and asking you to squeeze so that the tone of the anal sphincter can be assessed.
Test 2 – Anorectal Manometry
A fine probe will be inserted a short distance into your bottom and we will ask you to squeeze or cough to measure your sphincter muscle strength. For some patients we will assess rectal sensation which is done with a very small balloon on the end of the probe and you will be asked about what you are able to feel.
Test 3 – Anal Ultrasound
This involves inserting a probe (about the thickness of a finger) a few centimeters into the back passage. The probe stays there for a few minutes so that an ultrasound of the anal canal can be performed.
Is there any special preparation?
No preparation is required. We would suggest that you try and empty your bowels before coming to the hospital and empty your bladder. You can eat and drink normally before the tests. The tests do not require any sedation or anaesthetic and you will be able to drive home afterwards and can return to work the same day if you wish.
If you are pregnant please discuss with the nurse prior to your appointment as we will not perform any of these tests when pregnant unless you are in your third trimester (28-40) weeks.
What are the risks and side effects of the tests?
These tests are safe and should not be painful but may be slightly uncomfortable. There is a slight risk that the probe could damage the lining of the bowel, however, this is very unlikely as the probe is smooth and the nurse/consultant has specialised training in performing these tests.
What happens next?
You may find that your stools are a little looser for the rest of the day as during the manometry investigation there is a very small amount of water that runs into your bottom. You may feel more comfortable to visit the toilet after the appointment and wear a pad for precaution.
The nurse or consultant assessing you will discuss their findings during your visit. They will compose a letter for your GP, referring consultant and a copy of the letter will also be sent to yourself.
If you have any questions either before or after your appointment you can contact the Pelvic Floor Nurse specialist, Monday to Thursday on 01752 431166 or you may leave a message on this number, alternatively you can email at firstname.lastname@example.org where we will aim to answer any query within 48 hours.