Endoscopic Ultrasound (EUS) is both a treatment tool and an examination and diagnostic tool for the lining and walls of the upper gastrointestinal tract (esophagus, stomach and duodenum, which is the first part of the small intestine) and lower gastrointestinal tract (colon and rectum).
How is an Endoscopic Ultrasound Performed?
An endoscopic ultrasound is a procedure involving the use of an endoscope, a lighted, flexible tube, about the thickness of a finger. The doctor passes the tube through either the mouth or the anus to the area to be examined. The ultrasound component produces sound waves that create detailed, visual images of the digestive tract.
For an examination of the upper gastrointestinal tract, your throat will be numbed with a spray before the doctor gently passes the tube through your mouth, esophagus, and stomach into the duodenum. You will be able to breathe normally and burp if needed during the test. There usually is no pain associated with this test.
For an examination of the lower gastrointestinal tract, the doctor gently passes the tube through your rectum into the colon. There usually is no pain associated with this test.
Why Do I Need an EUS?
Endoscopic ultrasounds help your doctor treat or examine issues such as:
- Abdominal pain
- Abnormal weight loss
- Fecal incontinence
- An abnormality, such as a growth, that was detected during a prior endoscopy or by x-ray
- Diseases of the pancreas, bile duct, and gallbladder when other tests are inconclusive
EUS also helps your doctor determine the extent of certain cancers of the digestive and respiratory systems, accurately assessing the cancer’s depth and determining whether it has spread to adjacent lymph glands or nearby vital structures, such as major blood vessels.
If necessary, an instrument can be passed through the tube to take a small piece of tissue (a biopsy) for examination in the laboratory. Biopsies are done for many reasons and don’t necessarily imply cancer.