Endoscopic ultrasonography (EUS) is a test that looks into your digestive tract. An EUS is performed by a gastroenterologist (a specialist who specialises in the digestive system).

Healthcare providers use EUS to evaluate or diagnose:

An upper endoscopy procedure is an EUS procedure that examines the upper part of the digestive tract, including:

Your healthcare provider may perform endoscopic ultrasound-guided fine-needle aspiration. In this procedure, your provider uses EUS to guide a needle biopsy to remove a small sample of tissue or fluid. The sample goes to a lab where a lab specialist (pathologist) examines it for signs of disease, such as abnormal or cancerous cells.

Your healthcare provider will tell you what you should and shouldn't do before an EUS test. In general, you may need to:

An upper EUS test is an outpatient procedure. You'll go home the same day. Because you receive a sedative (anesthesia), someone needs to drive you home and stay with you for the remainder of the day. An upper EUS procedure takes about 60 minutes.

During an upper EUS test, you lie on your left side. A healthcare provider:

1. Gives you an IV sedative to help you relax.
2. Sprays your throat with a numbing medicine.
3. Places a plastic mouthguard in your mouth. The mouthguard protects your teeth and prevents you from biting down on the endoscope.
4. Inserts the ultrasound endoscope through your mouth, esophagus and stomach until it reaches the duodenum (top part of the small intestine). You shouldn't feel any pain. You will be able to breathe as usual.
5. Looks at ultrasound images on a monitor to examine your upper digestive tract, nearby organs, cysts or tumors.
6. If needed, uses the ultrasound images to thread a thin needle through the endoscope to take a sample of tissue or fluid.
7. Gently removes the endoscope and stops anesthesia. You slowly wake up in a recovery room.

Like an upper EUS test, a lower EUS test is an outpatient procedure. You can go home the same day. Someone should drive you home and stay with you throughout the day.

The procedure takes less than 60 minutes. Fine needle aspirations (needle biopsies) rarely take place during lower EUS procedures.

During a lower EUS test, you lie on your left side. A healthcare provider:

1. Gives you an IV sedative to help you relax.
2. Inserts the ultrasound endoscope through your anus and rectum into your large intestine (colon). You shouldn't feel any pain or discomfort and will be able to breathe as usual.
3. Looks at ultrasound images on a monitor to examine your lower digestive tract, including nearby organs, cysts or tumors.
4. Removes the endoscope gently and stops anesthesia, so you slowly wake up.

The sedative should wear off within 30 minutes to an hour. You may have:

These symptoms should go away within 24 hours after the test. You should take it easy for the rest of the day. You can resume work or other activities the next day.

An EUS test is a relatively safe procedure. Potential complications include:

Your healthcare provider will review EUS test findings with you. It may take a few weeks to get biopsy results back from the lab.

When to call the doctor

You should call your healthcare provider if you experience: