EUS allows your doctor to examine the wall of your upper and lower gastro-intestinal tract. The upper tract is the oesophagus, 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 bile duct and pancreas.
The doctor will use a thin and flexible tube called an endoscope, and pass it through your mouth or anus to the area that needs to be examined. The ultrasound component will then be turned on to produce sound waves that create visual images of the digestive tract.
EUS provides your doctor with more detailed pictures of your digestive tract anatomy. This information is used to diagnose the cause of conditions, such as abdominal pain or abnormal weight loss. In cases where your doctor has ruled out certain conditions, EUS can confirm this diagnosis and provide extra reassurance.
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, which can help your doctor determine its nature and decide 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 not eat or drink (not even water), usually six hours before the examination. You will be given clear instructions as to when you are to start fasting.
For EUS of the rectum or colon, your doctor 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 do not follow your doctor's instructions carefully on the necessary bowel preparation.
Most medications are safe to continue for the procedure. You should discuss this with your doctor prior to the examination, especially if you are taking warfarin, aspirin, ticlopidine, clopidogrel, or medication for high blood pressure or diabetes.
Depending on whether the area to be examined is in the upper or lower gastro-intestinal tract, the experience is almost identical to that of these procedures - OGD or colonoscopy.
You will be observed until the sedation has worn off, and will be discharged subsequently. Do not drive or operate any machinery until the next day, as the sedatives used will impair your reflexes.
At times, you may experience a mild sore throat but it will resolve in a few days. You will be able to eat normally within the same day and resume your normal activities the next day.
Complications are rare, but can occur. These include bleeding from a biopsy site, perforation or aspiration of stomach contents. Other uncommon risks include reactions to the sedatives used, infection, and complications from heart or lung diseases.
The possibility of complications increases slightly if a deep needle aspiration is performed during the EUS examination. These risks will be balanced against the potential benefits of the procedure and the risks of alternative approaches to the condition.
It is important to contact your doctor if you experience symptoms of severe chest/abdominal pain, fever or bleeding.
