Overview

Ultrasound uses high frequency sound waves to create an image of an area of the body. 

This is a widely used diagnostic test to examine the prostate gland which lies at the front of your bottom (rectum). 

A transrectal ultrasound scan (TRUS) can help to find the cause of a problem and can also be used to monitor an existing condition. 

The ultrasound is carried out by a sonographer or radiologist, both are trained professionals in this type of scan. 

How to prepare

You do not need a full bladder for your scan. 

You can continue to take any medicines prescribed by your doctor.

You should wear comfortable, loose-fitting clothing for your scan.

If you need a hoist (piece of medical equipment to help lift or move you safely), transport or a translator, please contact the radiology department.

Risks

A transrectal ultrasound scan is a very safe procedure with no side effects.

Other treatment options

If you do not want an internal scan, you can have a transabdominal pelvis ultrasound scan instead but it is not as accurate as a TRUS examination.

A transabdominal scan is where a probe is pressed on the outside of your body. For this scan you will need a full bladder. You will have to drink at least 500ml of water to fill your bladder, 30 minutes before your appointment. If you cannot hold the water and need to pee, please try not to completely empty your bladder.

Giving your permission (consent)

The sonographer or radiologist will ask you if you are happy for the scan to go ahead. If you decide to go ahead, you will be asked to sign a consent form. This states that you understand what it involves and agree to have the treatment. 

If you do not wish to have the scan or are undecided, please tell us. You can ask any questions before, during or after your scan. It is your decision and you can change your mind at any time. However not having the scan may delay your diagnosis as the doctors may not have all of the information that they need. 

A chaperone will be present for all intimate scans. You are welcome to bring a friend or family member to be present throughout the scan if you wish. 

Students or trainees may be present during the examination but only with your verbal consent. 

You can read more about our consent process.

During the transrectal ultrasound scan

The appointment is usually booked for 15 minutes. The scan itself usually takes a few minutes. This may vary depending on how clear the pictures are.

While we try to make sure that appointment times are kept, sometimes emergencies may need to take priority. We will inform you of any delays. Please be patient, but feel free to ask staff if you think you have been overlooked. 

• You should allow 1 hour in total for your appointment.
• You will be asked to undress from the waist down and lie down on a couch. 
• We will cover you with a sheet. 
• We will use paper tissue to cover your clothing to protect it from the gel.
• We use an ultrasound probe which is covered with a protective sheath. We apply a small amount of lubricating gel to the probe. 
• The probe is gently inserted into your bottom. 
• The probe will be moved into different positions so we can get the necessary images of the prostate. 
• Once the scan is completed, we will give you tissue to wipe away the gel and you can put your clothes back on.
• The lights in the room will be dimmed so that the pictures on the screen can be seen more clearly. 
• Selected images will be recorded so that they can be viewed later. 

Pain

Unless you are already in pain due to your symptoms, a transrectal ultrasound scan does not cause any pain. It might feel slightly uncomfortable but it should not hurt.

Results

Your scan will be reviewed and most often reported on the same day. The results will be sent back to your doctor who will discuss the report with you.

If your referring doctor is your GP then you should make an appointment for 2 weeks after your scan to discuss the results.

If your referring doctor is a consultant at Guy’s and St Thomas’ then you should have an outpatient appointment arranged. If not, please contact them to arrange a time to talk about the results and any treatment you may need.