Skip to main content

Endoscopic Ultrasonography


We offer Endoscopic Ultrasonography at our Credit Valley Hospital location.

Endoscopic Ultrasonography is a test where a thin, flexible tube called an endoscope that has a built-in miniature ultrasound probe on it is used to examine your esophageal and stomach linings as well as the walls of your upper and lower gastrointestinal tract. Ultrasound uses high frequency sound waves that bounce off internal tissues and produce echoes. The ultrasound echoes back to a monitor, forming a picture of the body tissue being examined.

 This test allows the doctor to:

  • examine your esophageal and stomach linings as well as the walls of your upper and lower gastrointestinal tract
  • study other organs that are near the gastrointestinal tract, including the lungs, liver, gall bladder and pancreas
  • take pictures of what is seen
  • take a small piece of tissue so that it can be examined under a microscope (this is called a biopsy)

Endoscopic Ultrasonography can be used to diagnose:

  • conditions that may cause abdominal pain
  • conditions that may cause abnormal weight loss
  • diseases of the pancreas, bile duct and gallbladder when other tests are inconclusive or conflicting

It can also be used to evaluate known abnormalities, including lumps or lesions, which were detected at a prior endoscopy or were seen on x-ray tests, such as a computed tomography (CT) scan.

Resources for Patients & Their Families

Why is Endoscopic Ultrasonography Used for Patients with Cancer?

If you have cancer of the digestive or respiratory systems, Endoscopic Ultrasonography can help your doctor determine how much it has spread. It allows your doctor to accurately assess the cancer’s depth and whether it has spread to nearby lymph glands or other vital structures, such as major blood vessels. In some patients, this test can be used to obtain a needle biopsy of a lump or lesion to help your doctor decide on the right treatment for you.

How to Prepare for Endoscopic Ultrasonography

For Endoscopic Ultrasonography of the upper gastrointestinal tract.
You should have nothing to eat or drink after midnight the day before your procedure. Your doctor will tell you when to start this fasting.

For Endoscopic Ultrasonography of the rectum or colon.
Your doctor will tell you to either consume a colonic cleansing solution or to follow a clear liquid diet combined with laxatives or enemas prior to the test. The procedure might have to be rescheduled if you don’t follow your doctor’s instructions carefully.

Can I Take My Current Medications If I’m Having Endoscopic Ultrasonography?

You can take most medications as usual until the day of the test. Tell your doctor about all medications that you’re taking and about any allergies you have. Anticoagulant medications (blood thinners such as warfarin or heparin) and clopidogrel may need to be adjusted before the procedure. Insulin also needs to be adjusted on the day of the test. In general, you can safely take aspirin and non-steroidal anti-inflammatory medications (ibuprofen, naproxen, etc.) before the test.

Check with your doctor in advance regarding these recommendations.

Check with your doctor about which medications you should take the morning of the test, and take them with a small sip of water.

If you have an allergy to latex, you should inform your doctor before to your test. Patients with latex allergies often need special equipment and may not be able to have the full test.

Do I Need to Take Antibiotics?

Antibiotics are not generally needed before or after this test. However, your doctor might prescribe antibiotics if you are having specialized Endoscopic Ultrasonography procedures, such as to drain a fluid collection or a cyst using Endoscopic Ultrasonography guidance.

What to Expect During Endoscopic Ultrasonography

Your doctor will pass the endoscope through your mouth or anus to the area to be examined. Your doctor will then use the ultrasound to create pictures of your digestive tract.

If your test will be looking at your upper gastrointestinal tract, you may be given a local anesthetic in the form of a spray to numb your throat before the test begins. Most often you will be given sedatives intravenously to help you relax. You will most likely begin by lying on your left side.

After you are relaxed, your endoscopist will pass the ultrasound endoscope through your mouth, esophagus and stomach into the duodenum. The instrument does not interfere with your ability to breathe. The actual examination generally takes less than 60 minutes. Most patients consider it only slightly uncomfortable, and many fall asleep during it.

If your test will be looking at your lower gastrointestinal tract you may not need any medications, but you will be given a sedative if the test will take a long time or if the instrument will be going a significant distance into your colon. You will start by lying on your left side with your back toward the doctor. Most Endoscopic Ultrasonography tests of the rectum generally take less than 45 minutes.

If a needle biopsy of a lesion or drainage of a cyst is performed during the test, then the procedure will be longer and may take up to two hours.

What Happens After Endoscopic Ultrasonography

If you were given sedatives, you will be monitored in the recovery area until most of the sedative medication’s effects have worn off. If you were given sedatives, you will not be allowed to drive after the procedure, even if you do not feel tired. You should arrange a ride home in advance. You should also plan to have someone stay with you after the examination, because the sedatives could affect your judgment and reflexes for the rest of the day.

If you had an upper Endoscopic Ultrasonography, your throat might be a little sore. You may use anesthetic (numbing) throat lozenges that are available at a pharmacy to help soothe your throat.

You might feel bloated because of the air and water that were introduced during the examination.

You will be able to eat after you leave the procedure area, unless you are told not to.

Your doctor will usually be able to give you the preliminary results the same day as the procedure, but the results of some tests, including biopsies, may take several days.

Are There Any Possible Complications?

Although complications can occur, they are rare. Bleeding might occur at a biopsy site, but it is usually minimal and rarely requires follow-up.

Other potential but uncommon risks of this test include a reaction to the sedatives used, aspiration of stomach contents into your lungs, infection, and complications if you have heart or lung diseases. One major but very uncommon complication is perforation, where a tear is made through the lining of the intestine. If this happens, it might need surgery to repair.

The possibility of complications increases slightly if a needle biopsy is performed during the test, including an increased risk of pancreatitis or infection. These risks must be balanced against the potential benefits of the procedure and the risks of alternative approaches to the condition.​