Endoscopic ultrasound

An endoscopy is a test to look inside your body. An endoscopic ultrasound (EUS) normally examines the lining of the food pipe (oesophagus), stomach and small intestine (duodenum).

A long, thin tube with a small camera inside, called an endoscope, is passed into your body through your mouth to look at these organs.

The ultrasound sensor on the end of the endoscope sends ultrasonic waves to and from your organs to get detailed information.

A small a tissue sample (biopsy) might be taken during the examination and sent to the laboratory for investigation. We use a small needle or small forceps to take a biopsy.

We want to involve you in decisions about your care and treatment. If you decide to go ahead, you will be asked to sign a consent form. This states that you agree to have the treatment and you understand what it involves.

If you would like more information about our consent process, please speak to a member of staff caring for you.

Please be aware that we are a teaching hospital. As St Thomas’ Hospital is one of the few centres in the UK that perform this test, there might be senior trainees performing this procedure under supervision or medical observers. Please let us know if you do not want other medical people to be present. This will not affect your treatment in any way.

Risks and complications

Although complications can happen, they are rare. There is a risk of the following happening to 1 in 1,000 people.

  • Bleeding which might need a blood transfusion.
  • Reaction to the sedatives, if used during the test.
  • Perforation (tearing) of the lining of the gastrointestinal tract, which might need surgery to repair.
  • Inflammation of the lungs (aspiration pneumonia), caused by inhaling the contents of the stomach. This is why it is important that you follow the instructions about not eating or drinking before the test.
  • Disturbance of crowned teeth or dental bridgework. It is important that you tell us about any crowns or bridgework before we start the test. Very rarely damage to your teeth can be caused by biting down hard on the mouth piece needed to keep your mouth open during the procedure.

If a fine needle aspiration (FNA) is used to take a biopsy, the risk increases to about 1 in every 100 patients for each of the above risks.

If a biopsy is taken from the pancreas there is a risk of pancreatitis (inflammation of the pancreas gland) resulting in pain which may be severe in a few cases.

If a biopsy is taken from a fluid collection there is a small risk of infection and a course of prophylactic (preventative) antibiotics might prescribed for you.

If there is a complication, you might need to have a blood transfusion or have surgery to treat the problem.

Your doctor or specialist nurse will discuss the possible complications with you before you sign the consent form.

Other test options

Other tests are available, such as CT or MRI scans, or tissue samples taken using a needle through the skin, can also be used, but they might not give the same detail as this examination.

If your health gets worse

If your health has got worse since your clinic appointment, contact the clinical nurse specialist (CNS) helpline for advice on 020 7188 2673.

If you need to contact the consultant medical team, phone the secretary on 020 7188 2491

Resource number: 0451/VER8
Last reviewed: February 2023
Next review: May 2024


Contact us

If you need to change or cancel your appointment, please call 020 7188 8887.

Contact the endoscopy unit for advice from Monday to Friday, 9am to 5pm.

Nurse in charge: 020 7188 7188 ext 54059

St Thomas' reception desk: 020 7188 7188 ext: 54046

In an emergency, out of hours (6pm until 8am the next day and on Saturday or Sunday). Phone 020 7188 7188 and ask to be put through to the on-call gastroenterology registrar.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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