Anorectal Physiology Investigations – an investigation for patients with bowel problems

Patient Experience

  • Reference Number: HEY-022/2022
  • Departments: GI Physiology
  • Last Updated: 22 August 2022


This leaflet has been produced to give you general information. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion. If after reading it you have any concerns or would like further explanation, please call the Department of GI Physiology directly on 01482 624036.

What are Anorectal Physiology investigations?

You have recently been troubled by bowel symptoms (e.g. faecal incontinence and/or constipation). Following discussion with your doctor, they have advised that you have Anorectal Physiology investigations.

Anorectal Physiology investigations are used to assess the muscles in the anal canal and rectum.

Depending on your symptoms, the tests performed may include:

  • pressure studies (manometry) which measures muscle function in the anal canal and rectum
  • rectal sensation testing
  • an Endoanal Ultrasound scan, which visualises the muscles of the anal canal using an ultrasound probe

Why do I need Anorectal physiology?

Anorectal physiology investigations will help your healthcare professional to identify if there are any problems with your anal canal, rectum and the nerves supplying them.

Can there be any complications or risks?

As with all procedures, there are some risks associated with Anorectal Physiology investigations. These include occasional minor discomfort, minor bleeding and, very rarely, perforation of the bowel wall.

However, the overall risk of having a problem when undergoing these investigations is very low.

Anorectal Physiology investigations are not usually performed during pregnancy. If you are currently pregnant, please call the Department of GI Physiology directly on 01482 624036.

How do I prepare for Anorectal physiology?

Please read this information leaflet carefully. If you wish, share the information it contains with your partner and/or family so that they can be of help and support.

You can eat and drink as normal, and you will be able to resume work or your normal activities after your Anorectal Physiology appointment.

What will happen?

You should go to the Department of GI Physiology, which is situated next to Ward 14 (1st floor) at Castle Hill Hospital.

You will be seen by a member of staff from the Department of GI Physiology. You will be asked to remove your lower clothing and lay on your left side with your knees drawn up, on an examination couch. You will covered with a blanket as much as possible to protect your privacy and dignity.

The healthcare professional may then conduct a quick and simple examination of your anal canal and rectum before placing a small measurement probe into your bottom. The probe has a small balloon on the end, which can be used to mimic the sensations of wanting to go to the toilet. You will be asked to squeeze, cough and push down, to obtain accurate pressure measurements of the muscles in your bottom. The probe may be in place for up to 30 minutes.

After the pressure measurements are completed, an Endoanal Ultrasound scan may be performed. To do this, a small ultrasound probe will be placed into your bottom to visualise the muscles of your anal canal. An Endoanal Ultrasound scan takes approximately 5 minutes.

Your complete appointment could take up to 60 minutes. Once your Anorectal Physiology investigations are completed, you will be able to get dressed and return to your normal activities.  

What will happen afterwards?

After your appointment, your results will be sent to the consultant who referred you for Anorectal Physiology investigations.

This leaflet was produced by the Department of GI Physiology, Hull University Teaching Hospitals NHS Trust and will be reviewed in 3 years in August 2025.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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