An EUS, or endoscopic ultrasound, is an outpatient procedure used to closely examine the tissues in the digestive tract. The procedure is done using a standard endoscope and a tiny ultrasound device. The ultrasound sensor sends back visual images of the digestive tract to a screen, allowing the physician to see deeper into the tissues and the organs beneath the surface of the intestines. An EUS allows the physician to get a much clearer view of an area, making this a very reliable test and preferable to more invasive procedures.

EUS can be used to evaluate:

  • blood vessels
  • gallstones inside the gallbladder and bile duct
  • pancreas;
  • rectum abnormalities
  • tumors and lymph nodes underneath the intestinal wall
  • existing tumor growth; and
  • tumors that appear benign

The procedure can also be used to take biopsies of tumors.

Frequently Asked Questions about EUS

Q.  What exactly is an endoscope?
A. An endoscope is a lighted, flexible tube with a tiny, optically sensitive computer chip at the end. As the physician moves it through the gastrointestinal tract, electronic signals are transmitted from the scope to a computer that displays the image on a video screen.  An open channel in the scope allows other instruments, like the ultrasound device, to be passed through it.

Q.  Why does the physician need to see into the tissues of the digestive tract?
A.  When patients have symptoms of more common problems in the gastrointestinal system, like stomach ulcers or intestinal polyps, physicians use standard endoscopic procedures.  Sometimes, the physician needs to get a better look at the area of concern. In those cases, the ultrasound is recommended because it helps provide a more life-like picture of your condition and allows the physicians to make a much more accurate diagnosis.

Q.  What happens during the EUS procedure?
A.  The actual exam is fairly simple and usually takes 20 to 40 minutes. You will be given a mild sedative and the physician will ask you to lie on your left side. For this procedure, the endoscope can be inserted either into the mouth or the rectum. If the endoscope is being inserted in the mouth, an anesthetic spray will be used to numb the back of your throat.  Once the endoscope has been gently guided into position, the ultrasound device will begin sending images to a video screen.  Once the procedure is completed, you will be taken to the recovery area.

Q.  Is any preparation necessary before the procedure?
A.  When an EUS is done on the upper digestive tract, you cannot eat or drink anything for eight hours before the procedure.  If it is being done on the lower intestine, the colon must be clean. In this case, your physician will provide you with instructions for a liquid diet and laxatives or an enema to cleanse the lower bowel. Your physician may ask you to stop taking certain medications, such as aspirin, before the procedure. Also, you should have someone drive you to and from the test.

Q. What happens after the procedure?
A. After the examination, your physician will explain the results. If the effects of the sedatives are prolonged or a biopsy was taken, the physician may suggest a follow-up appointment to review the results.

Q. Should I expect complications or side effects?
A.  In general, an EUS is a very safe procedure. If your procedure is being done on the upper GI tract, you may have a sore throat for a few days.  As a result of the sedation, you should not drive, operate heavy machinery or make any important decisions for up to six hours following the procedure.  There is a slight risk of the endoscope tearing the intestinal tract, which would require surgery. Rarely, bleeding does occur if a biopsy is taken. Serious complications are extremely uncommon.

This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or procedure.