Endoscopic Ultrasound

Also known as: EUS.

What is endoscopic ultrasound?

Ultrasound is a medical imaging test that uses sound waves to produce pictures of organs and systems inside the body. When more detailed images of portions of the digestive system are needed, a patient might receive an endoscopic ultrasound. This involves performing an ultrasound using an endoscope, or a long, thin, flexible tube that is passed inside the body.

What happens during the procedure?

After receiving medicine to help with relaxation and induce sleep the endoscope is inserted into the patient’s mouth and into the esophagus and stomach. The endoscope has an ultrasound within it that creates the images of the inside of the body. Then the endoscope is removed.

Is any special preparation needed?

You may need to avoid food, drink or medication for a set period of time before the procedure. In some cases, you might be required to take a laxative or enema.

What are the risk factors?

Bleeding, infection or perforation of surrounding tissue are potential complications of endoscopic ultrasound.

Reviewed by: Carrie Firestone Baum, MD

This page was last updated on: September 16, 2025 12:39 PM