Endoscopic Ultrasound

What is an Endoscopic Ultrasound?

Endoscopic ultrasound, also known as EUS or endoscopic ultrasonography, is a test that gastroenterology specialists can use to diagnose problems of the gastronintestinal (GI) walls and surrounding organs like the liver, pancreas, gallbladder and lungs. Unlike the devices used during colonoscopy and other traditional endoscopic procedures, which have a camera at the tips, EUS requires an endoscope with a tiny, ultrasound tool at the end. This endoscope is inserting via a patient’s mouth or anus and guided toward whichever area of the body needs to be checked for disease. Visuals are captured with sound wave technology. Since most EUS exams require sedation, most patients say that they don’t remember their procedure once it’s over. However, soreness is normal during the days after the test.

Why Should I Get an Endoscopic Ultrasound?

Endoscopic ultrasounds produce medical images with a significant amount of detail without having to resort to open or laparoscopic surgery. They can also help a doctor get a better look at growths and other abnormalities found during prior exams, such as CT scan. For example, unlike a final x-ray image, the final image of an endoscopic ultrasound will display accurate information about how deep into the tissue and other organs a growth has spread. Accordingly, EUS is often turned to as a method of monitoring and treatment cancers of the respiratory and digestive systems. During EUS, biopsy of cancerous tissue can be done for diagnosis and treatment as well. If you are experiencing symptoms such as unexplainable abdominal pain or sudden weight loss, EUS might be a good option for you. 

How Do I Prepare for an Endoscopic Ultrasound?

Since patients are usually put under sedation during EUS exams of the upper GI tract, it’s necessary to schedule for a friend or family member to either come with you to your appointment or pick you up afterward. For exams of the lower GI tract, sedation depends on how far up the colon your doctor needs to test.

You’ll also need to prepare your body for EUS by refraining from food and drink for at least 6 hours prior to the examination. If you are undergoing colorectal exams, you’ll need to practice bowel prep as well, drinking several gallons of laxative in order to empty your colon the night before the endoscopic ultrasound. Sometimes an enema is used several times right before the endoscope is inserted, to ensure clean viewing. Stay in communication with your doctor about current medications and allergies, as you may need to have special advice before the procedure can be performed.


Reviewed 12/29/2011 by David M. Nolan, M.D.
Diplomate of the American Board of Internal Medicine, 2011
Currently a Fellow of Gastroenterology, at UCI 2011-2014