Gastrointestinal physiology

Faecal incontinence and disorders of evacuation have a huge impact on quality of life.

Lower gastrointestinal or anorectal physiology involves a range of tests which assess the muscles, nerves and coordination of the back passage (anal canal and rectum) in order to help direct future treatments.

The tests patients are referred for may include manometry (pressure studies), electrophysiology (nerves studies), rectal sensitivity testing (tests of perception) and/or ultrasound imaging (to look for any injuries to the muscles of the anal canal).

These tests are performed by a specialist Clinical Scientist following referral from a Surgeon or Gastroenterologist.

What are anorectal physiology tests?

Anorectal physiology tests should not be painful but may be slightly uncomfortable. You do not require sedation and the tests should not cause any discomfort afterwards. These tests may include the following:

Digital rectal examination
Anorectal manometry
Rectal sensory test
Balloon expulsion
Endoanal ultrasound

We explain each of these in more detail below.

What is a digital rectal examination?

A digital rectal examination is an examination of the back passage (anal canal and rectum) by a physiologist/healthcare scientist. You may have already undergone a digital rectal examination before your attendance at the unit.

The physiologist/healthcare scientist will insert a gloved finger into the back passage. They may then ask you to squeeze as if you are trying to stop yourself from emptying your bowel /passing stool (poo) and then push as if you are trying to pass a stool.

What is anorectal manometry?

Anorectal manometry is a test which measures the pressure in the back passage. In order to measure these pressures a physiologist/healthcare scientist will insert a specially designed tube called a manometry catheter into the back passage. The tube is roughly the thickness of a little finger and has a balloon on the tip.

Once the tube is in position we may ask you to perform certain exercises or movements such as squeezing (described above), coughing and pushing (described above). The pressures measured during these exercises are recorded on a screen. This helps the physiologist/healthcare scientist understand how well the muscles work at the back passage.

What is a rectal sensory test?

As described above the tube already put into the back passage has a small balloon attached to the tip. The physiologist/healthcare scientist will fill this balloon with varying amounts of air. The air will attempt to mimic the sensation of wanting to go to the toilet. Please do not worry as this will not actually make you go to the toilet.

The air within the balloon stimulates these sensations and will help the physiologist/healthcare scientist assess your ability to sense the volumes of air in the back passage.

What is a balloon expulsion test?

A balloon expulsion test is where a small balloon attached to a thin tube is passed into the back passage. The balloon is then inflated with a small amount of water (50 ml). You will then be asked to push the balloon out whilst sitting on a toilet/commode. We will leave the room whilst you try to expel the balloon.

This test will help the physiologist/ healthcare scientist understand how well the muscles are working at the back passage.

What is endoanal ultrasound?

Endoanal ultrasound is an imaging technique which enables us to look at the structure of the muscles at the back passage. This uses a probe about the size of an index finger which is covered in a sheath. Please let us know if you have an allergy to latex or nitrile. The probe is passed into the back passage and images are taken which show up on a screen. The test should be painless and lasts for only a few minutes.

What are the risks associated with anorectal physiology tests?

As with all medical procedures there are some small risks. This includes perforation of the bowel wall and bleeding. The risk of perforation is very small and is considered far less than the risk associated with colonoscopy which investigates the entire large bowel (we investigate only the last few inches of the bowel).

There is also a risk of technical/computer problems which although unlikely could mean that you may need to have some of the tests repeated. The overall risk of having a problem when undergoing these tests is considered very low.

What are the benefits of having anorectal physiology tests?

The benefits of these tests are that we may help to provide a reason for your symptoms. By proving a reason(s) for your symptoms this may help your consultant develop a better treatment plan designed for you. This could result in a better way of treating your symptoms.

What do I need to do before the tests?

Please complete the anorectal physiology patient assessment form and bring this to your appointment. If you are unable to complete this then we will help on the day.

We hope that by answering these questions at home before your appointment will enable you to give the physiologist/healthcare scientist as much information as you feel will help us to understand your symptoms and the reasons why you have them.

No special preparation is needed. On the day of your test you may eat and drink as normal. You may also go to the toilet as you normally would. You do not need to use a specialist bowel preparation. You should take any medications as you would do normally. You will not be sedated and so you may drive to and from your appointment. You may return to work after your appointment.

What can I expect when I arrive at the unit?

When you arrive for your appointment we will take you to a private area. We will ensure that your comfort and dignity are preserved at all times.
Newcastle upon Tyne Hospitals are teaching hospitals and as such have a responsibility to ensure that students receive a high standard of training. Occasionally there may be a trainee with relevant experience performing the procedure or a trainee or assessor observing the procedure in the department. You will be told beforehand and asked your permission for a student to be present. It is your right to decline anything you are not comfortable with and this will not affect your care.
We will talk about your symptoms and go through your assessment sheet.
We will describe the tests you need and will give you an opportunity to ask any questions which you may have.
We must seek your consent before the tests. Therefore, once the physiologist/healthcare scientist has explained the risks and benefits we will ask you to complete a consent form. If you are unsure or have any hesitation then please ask further questions. You can of course stop any test at any point.
We will ask you to remove your lower items of clothing and/or wear a gown. You will be asked to cover yourself with a sheet and lie on a couch on your left side with your knees drawn up.

Who will do these tests?

An appropriately qualified physiologist/healthcare scientist or a trainee under close supervision will do the test. There will be two members of staff present in the room throughout most of the tests. These tests can be performed by male and female members of staff. If you would prefer two staff members of certain gender please contact us.

When and where do I need to go for my appointment?

Your appointment is held in Ward 45, Leazes Wing at the Royal Victoria Infirmary (RVI).

Please go to the reception desk at the entrance of the ward.

How can I rearrange or cancel my appointment?

Please contact the booking line or secretary as detailed in your appointment letter.

What do I do if I need an interpreter?

Please contact the booking line or secretary as detailed in your appointment letter. They will be able to arrange an interpreter.

Can a family member or friend act as an interpreter for me?

Unfortunately, it is a Trust policy that family members or friends cannot act as your interpreter. Family members or friends are not able to enter the clinic room with you. We will therefore arrange an independent interpreter for you. If you need this then please contact the secretary using the telephone number in your appointment letter.

What do I do if I need to arrange hospital transport?

Ambulance transport is available to those who have a medical need. For information on how to request ambulance transport please telephone the North East Ambulance Service (NEAS) or visit their website for guidance on eligibility. If your circumstances or appointment changes please remember to re-arrange your transport by contacting NEAS.

Telephone: 0191 2139000

North East Ambulance Service

Who do I contact if I need further information or have questions about my appointment?

Please contact the secretary on the number detailed in your appointment. Alternatively, you may email enquiries directly to the anorectal physiology team and they will be happy to help:

Email: [email protected]

Can I bring someone with me to my appointment?

You can bring an adult (over 18) to your appointment. However, they will be asked to remain in the waiting area whilst you are undergoing the tests. Please do not bring any children under the age of 18 with you. If you need to arrange childcare then we are happy to rearrange your appointment.

How long do these tests take?

We would expect that the appointment should last around one hour.

What happens after the tests and when do I get my results?

After the tests you may return home or go back to work.

Unfortunately, we are not able to provide you with results on the day. Instead, we will put together your results and send them to your consultant within four weeks. They will discuss them with you at your next appointment.