||Understanding EUS (Endoscopic
You've been referred to have an endoscopic
ultrasonography, or EUS, which will help your doctor, evaluate or
treat your condition. This brochure will give you a basic understanding
of the procedure - how it is performed, how it can help, and what
side effects you might experience. It can't answer all of your questions,
since a lot depends on the individual patient and the doctor. Please
ask your doctor about anything you don't understand. Endoscopists
are highly trained specialists who welcome your questions regarding
their credentials, training and experience.
What is EUS?
EUS allows your doctor 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 endoscopist will use a thin, flexible tube called an endoscope.
Your doctor will pass the endoscope through your mouth or anus to
the area to be examined. Your doctor then will turn on the ultrasound
component to produce sound waves that create visual images of the
Why is EUS done?
EUS provides your doctor more detailed pictures of your digestive
tract anatomy. Your doctor can use EUS to diagnose the cause of conditions
such as abdominal pain or abnormal weight loss. Or, if your doctor
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, which can help your doctor 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.
Why is EUS used for patients with cancer?
EUS helps your doctor determine the extent of certain cancers
of the digestive and respiratory systems. EUS allows your doctor to
accurately assess the cancer's depth and whether it has spread to
adjacent lymph glands or nearby vital structures such as major blood
vessels. In some patients, EUS can be used to obtain tissue samples
to help your doctor determine the proper treatment.
How should I prepare for EUS?
For EUS of the upper gastrointestinal tract, you should have
nothing to eat or drink, not even water, usually six hours before
the examination. Your doctor will tell you when to start this 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 don't
follow your doctor's instructions carefully.
What about my current medications or allergies?
Tell your doctor in advance of the procedure about all medications
that you're taking and about any allergies you have to medication.
He or she will tell you whether or not you can continue to take your
medication as usual before the EUS examination. In general, you can
safely take aspirin and nonsteroidal anti-inflammatories (Motrin,
Advil, Aleve, etc.) before an EUS examination, but it's always best
to discuss their use with your doctor. Check with your doctor about
which medications you should take the morning of the EUS examination,
and take essential medication with only a small cup of water. If you
have an allergy to latex you should inform your doctor prior to your
test. Patients with latex allergies often require special equipment
and may not be able to have an EUS examination.
Do I need to take antibiotics?
Antibiotics aren't generally required before or after EUS examinations.
But tell your doctor if you take antibiotics before dental procedures.
If your doctor feels you need antibiotics, antibiotics might be ordered
during the EUS examination or after the procedure to help prevent
an infection. Your doctor might prescribe antibiotics if you're having
specialized EUS procedures, such as to drain a fluid collection or
a cyst using EUS guidance. Again, tell your doctor about any allergies
Should I arrange for help after the examination?
If you received sedatives, you won't be allowed to drive after the
procedure, even if you don't feel tired. You should arrange for a
ride home. You should also plan to have someone stay with you at home
after the examination, because the sedatives could affect your judgment
and reflexes for the rest of the day.
What can I expect during EUS?
Practices vary among doctors, 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 doctor will examine a significant distance into
the colon. You will start by lying on your left side with your back
toward the doctor. Most EUS examinations of the lower gastrointestinal
tract last from 10 to 30 minutes.
What happens after EUS?
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 doctor generally can inform you of the
results of the procedure that day, but the results of some tests will
What are the possible complications of EUS?
Although complications can occur, they are rare when doctors with
specialized training and experience perform the EUS examination. Bleeding
might occur at a biopsy site, but it's usually minimal and rarely
requires follow-up. You might have a sore throat for a day or more.
Nonprescription anesthetic-type throat lozenges and painkillers help
relieve the sore throat. Other potential, but uncommon, risks of EUS
include a reaction to the sedatives used; backwash of stomach contents
into your lungs; infection; and complications from heart or lung diseases.
One major, but very uncommon, complication of EUS is perforation.
This is a tear through the lining of the intestine that might require
surgery to repair. The possibility of complications increases slightly
if a deep needle aspiration is performed during the EUS examination.
These risks must be balanced against the potential benefits of the
procedure and the risks of alternative approaches to the condition.
If you have any questions about your need for EUS, alternative approaches
to your problem, the cost of the procedure, methods of billing or
insurance coverage, do not hesitate to speak to your doctor or doctor's
office staff about it. ASGE Patient Education brochures are available
for purchase in packs of 50. Download order form.
Upper EUS Preparation
ASGE - The Source for Colonoscopy and Endoscopy
The preceding information is intended only to provide general information
and not as a definitive basis for diagnosis or treatment in any particular
case. It is very important that you consult your doctor about your