Treatments and tests

Endoscopic rectal ultrasound

What is an endoscopic rectal ultrasound?

Endoscopic rectal ultrasound is used to look inside your rectum. A flexible tube (endoscope) with an ultrasound tip on it is passed into your rectum. The ultrasound tip, which is connected to a computer by the tube, uses soundwaves to make pictures of the inside of your rectum.

Endoscopic rectal ultrasound can be used to look at:

  • cancer in the rectum
  • polyps in the rectum.

Please note: endoscopic rectal ultrasound is different to a colonoscopy.

Terms explained

Polyp – a growth on the lining of the colon. These growths can benign, but can sometimes become cancerous later on.

Benefits of an endoscopic rectal ultrasound

  • Can show cancer at an early stage.
  • Can show if cancer has spread and how far (staging of cancer).
  • Does not use radiation.

Risks of an endoscopic rectal ultrasound

Your doctor knows the risks of having an endoscopic rectal ultrasound. Your doctor will consider the risks before recommending you to have an endoscopic rectal ultrasound. Possible risks include:

  • bleeding
  • your rectum or colon may be hurt or punctured (this is very rare).


  • Bring your referral letter or request form and all X-rays taken in the last 2 years with you.
  • Leave the X-rays with the radiology staff as the doctor may need to look at them. The radiology staff will tell you when these are ready to be picked up.
  • Leave all jewellery and valuables at home.

Tell your doctor before the procedure

  • If you are or may be pregnant.
  • If you are taking any blood thinning medication (Warfarin, regular aspirin).

Just before the procedure

  • You may be given an enema to help clear your rectum of faeces (poo).
  • You will be given a gown to wear.
  • You may be asked to remove any metal objects.

What happens during an endoscopic rectal ultrasound

You will be asked to lie on a table on your side. A flexible tube with an ultrasound tip will be passed into your rectum. You may be asked to change position so that the doctor can see inside your rectum clearly.

The doctor will look at the pictures of inside your rectum on a screen, while the tube is being slowly pulled back out. This procedure may feel a little bit uncomfortable however a sedative is not usually needed.

The doctor may need to take a sample from inside your rectum. A sedative is not normally needed.

The endoscopic rectal ultrasound usually takes between 30 minutes and an hour including time taken to get ready


You have the right to refuse an examination and may do so if you wish. You may be asked to fill in a consent form.

When will I get the results?

The amount of time it takes for you to get your results will differ depending on where you get your scans done. The radiology doctor will look at the pictures and write a report. The pictures may be on films or on a CD.

Ask whether you should wait to take the pictures and report with you, or whether they will be sent to your doctor.

Your doctor will need to discuss the report with you. You will need to make an appointment to do this.

After an endoscopic rectal ultrasound

You will be able to go soon after the endoscopic rectal ultrasound has finished and can continue with normal activities.

If you had a sedative:

  • You must not drive a car or take public transport for 24 hours afterwards.
  • You must have someone with you for 24 hours afterwards.
  • You must not operate machinery for the rest of the day.

Costs of an endoscopic rectal ultrasound

For an Australian patient in a public hospital in Western Australia:

  • public patient – no cost to you unless advised otherwise
  • private patient – costs can be claimed through Medicare and your health insurance provider

For a patient in a private hospital or private imaging site in Western Australia – ask your doctor or the staff where you are having your test done.

Where to get help

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

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