Endoscopic Ultrasound (EUS)

An endoscopic ultrasound (EUS) is a test to look at the inside of your gastrointestinal (GI) tract. It's commonly used to look for cancers or growths in the esophagus, stomach, pancreas, liver, and rectum. It can help to stage cancer (to see how advanced a cancer is) both inside and outside of the GI tract. EUS may also be used to help diagnose certain diseases. It can also drain sacs of fluid in the body, like cysts or abscesses. This test does not expose you to harmful radiation.

What is EUS?

EUS shows both ultrasound images and live video of the GI tract. During the test, a flexible tube called an endoscope (scope) is used. At the end of the scope is a tiny video camera and light. The video camera sends live images to a monitor. The scope also contains a very small ultrasound device. This uses sound waves to create images and send them to a monitor.

A needle is passed through the scope. The needle can be used take a small sample of tissue for testing. This is called a biopsy. The needle can also be used to take a sample of fluid. This is called fine-needle aspiration.

Risks and possible complications

Risks and possible complications of an EUS include:

• Bleeding.

• Infection.

• A hole (perforation) in the digestive tract.

• Risks of sedation or anesthesia.

• Pancreatitis.

Before the test

• Tell your health care provider all the medicines that you take. This includes vitamins, herbs, and over-the-counter medicines for allergies, colds, fevers, and aches. It also includes all prescribed medicines, such as any blood thinners like warfarin, clopidogrel, ibuprofen, or daily aspirin. Ask your provider if you need to stop taking some or all of them before the test.

• You may get antibiotics to take before or after the test. This depends on the area being studied and what is done during the test. These medicines help prevent infection.

• Carefully follow your provider's directions to prepare for the test. Directions may include:

  • If you’re having an EUS of the upper GI tract (esophagus, stomach, duodenum, pancreas, liver):

    • Don't eat or drink for 6 hours before the test. You may be asked not to eat or drink after midnight the night before. This is to make sure that your stomach is empty for the procedure.

  • If you’re having an EUS of the lower GI tract (rectum):

    • Before the test, do bowel prep as directed to remove stool from your rectum. This may involve having only clear liquids and using a laxative (liquid or pills) the night before. Or you may have one or more enemas the morning of the test. This is to make sure that your intestines are empty of food and stools for the procedure. Follow your provider's instructions carefully.

    • Don't eat or drink for 6 hours before the test.

• Your health care provider may tell you to take any of your medicines 4 hours before the test with just little sips of water.

• Be sure to arrive on time at the facility. Bring your identification and health insurance card. Leave valuables at home. Wear loose and comfortable clothes. If you have them, bring X-rays, CT scans, MRI reports, or other test results with you.

Tell your health care provider

For your safety, tell the health care provider if you:

• Take insulin. Your dose may need to be changed on the day of your test.

• Take medicines for heart, kidney, liver, and lung problems.

• Have implanted electromedical devices such as cardiac pacemakers, defibrillators, stents, or valves.

• Have had stomach or bowel surgery, problems with swallowing food or passing stools, or other GI problems.

• Are allergic to latex.

• Have any other allergies.

• Are taking blood thinners.

• Are pregnant or think you may be pregnant.

During the test

An endoscopic ultrasound usually takes place in a hospital. The procedure itself may take 1 to 2 hours. You will likely go home soon afterward. During the test:

• You lie on your left side on an exam table.

• An intravenous (I.V.) line will be put into a vein in your arm or hand. This line supplies fluids and medicines. To keep you comfortable during the test, you will be given a sedative medicine. This medicine prevents discomfort and will make you sleepy.

• If you are having an EUS of the upper GI tract, local anesthetic may be sprayed in your throat. This will help you be more comfortable as the health care provider inserts the scope. The provider then gently puts the flexible scope into your mouth or nose and down your throat.

• If you’re having an EUS of the lower GI tract, the provider gently puts the flexible scope into your anus.

• Air or carbon dioxide gas may be pumped in your GI tract during the test to move the tube more easily.

• During the test, the scope sends live video and ultrasound images to nearby monitors. These are used to examine your GI tract. Some procedures, such as drainage, are done as needed.

• The health care provider may discuss the results with you soon after the test. Biopsy results take  several days.

• In most cases, you can go home within a few hours of the test. When you leave the facility, have an adult family member or friend drive you, even if you don't feel very sleepy.

After the test

Here is what to expect after the test:

• You may feel tired from the sedative. This should wear off by the end of the day.

• If you had an upper digestive endoscopy, your throat may feel sore for 1 to 2 days. Over-the-counter sore throat lozenges and spray should help.

• You can eat and drink normally as soon as the test is done.

• You may feel mild bloating (swelling) or cramping due to air or carbon dioxide gas. These should go away within 24 hours.

When to call your health care provider

Contact your health care provider if you have:

• A fever of 100.4° F ( 38.0° C) or higher, or as advised by your provider.

• Shortness of breath.

• Vomiting of blood, blood in stool, or black stools.

• Coughing or a hoarse voice that won’t go away.

• Belly pain that gets worse.