What to expect
Endoscopic Ultrasonography (EUS) allows your physician to examine the lining and the walls of your upper and lower gastrointestinal tract. The upper tract is the esophagus, stomach and duodenum; the lower tract includes your colon and rectum. EUS is also used to study internal organs that lie next to the gastrointestinal tract, such as the gall bladder and pancreas.
Your physician will use a thin, flexible tube called an endoscope and pass the endoscope through your mouth or anus to the area to be examined. Your physician then will turn on the ultrasound component to produce sound waves that create visual images of the digestive tract.
EUS provides your physician more detailed pictures of your digestive tract anatomy. Your physician can use EUS to diagnose the cause of conditions such as abdominal pain or abnormal weight loss. Or, if your physician has ruled out certain conditions, EUS can confirm your diagnosis and give you a clean bill of health.
EUS is also used to evaluate an abnormality, such as a growth, that was detected at a prior endoscopy or by X-ray. EUS provides a detailed picture of the growth, that can help your physician determine its nature and decide upon the best treatment. In addition, EUS can be used to diagnose diseases of the pancreas, bile duct and gallbladder when other tests are inconclusive.
For EUS of the upper gastrointestinal tract, you should have nothing to eat or drink, not even water, usually for 6 hours before the examination. Your physician will tell you when to start this fasting.
For EUS of the rectum or colon, your physician will instruct you to either consume a large volume of a special cleansing solution or to follow a clear-liquid diet combined with laxatives or enemas prior to the examination. The procedure might have to be rescheduled if you don’t follow your physician’s instructions carefully.
Practices vary among physicians, but for an EUS examination of the upper gastrointestinal tract, your endoscopist might spray your throat with a local anesthetic before the test begins. Most often you will receive sedatives intravenously to help you relax. You will most likely begin by lying on your left side. After you receive sedatives your endoscopist will pass the ultrasound endoscope through your mouth, esophagus and stomach into the duodenum. The instrument does not interfere with your ability to breathe. The actual examination generally takes between 15 to 45 minutes. Most patients consider it only slightly uncomfortable and many fall asleep during it.
An EUS examination of the lower gastrointestinal tract can often be performed safely and comfortably without medications, but you will probably receive a sedative if the examination will be prolonged or if the physician will examine a significant distance into the colon. You will start by lying on your left side with your back toward the physician. Most EUS examinations of the lower gastrointestinal tract last from 10 to 30 minutes.
If you received sedatives, you will be monitored in the recovery area until most of the sedative medication’s effects have worn off. If you had an upper EUS, your throat might be sore. You might feel bloated because of the air and water that were introduced during the examination. You’ll be able to eat after you leave the procedure area, unless you’re instructed otherwise.
Your physician generally can inform you of the