Endoscopic Ultrasound

Endoscopic Ultrasound (EUS) combines endoscopy and ultrasound to examine the walls and lining of your upper and lower gastrointestinal tract as well as the surrounding tissue and organs. Using a specialized endoscope with an ultrasound probe on the tip sound waves create high quality visual images of the organs and structures inside the digestive tract. An Upper Endoscopy involves the esophagus (swallowing tube), stomach and duodenum (first portion of the small intestine). While a lower endoscopy includes your colon and rectum. EUS is also used to examine organs near the gastrointestinal track including the gall bladder, pancreas, liver and bile ducts and obtain tissue samples. Using ultrasound guidance a needle is passed through the endoscope into enlarged lymph nodes or suspicious tumors from which cells are removed and later examined by a pathologist. This process of obtaining tissue is referred to as fine needle aspiration (FNA).

There are many reasons your doctor may request a EUS Endoscopic Ultrasound. The most common include the following symptoms or diseases:

Preparation for an Upper EUS is minimal. Your stomach should be completely empty. You should have nothing to eat or drink for 8 hours prior to the examination. Your doctor will be more specific about the time to begin fasting depending on the time of day that your test is scheduled. You should not smoke or chew gum for at least 6 hours prior to the exam.

Preparation for a Lower EUS is similar to that of a colonoscopy. Your colon must be clean in order for your physician to get the best view possible. A special liquid diet followed by a laxative preparation is necessary to clear out any waste or solid residue. There are several different types of preparations and your physician will determine which is best for you. Some require a prescription and usually at least 24 hours of following a diet consisting of “clear” liquids).

Download Clear Liquids

It is very important that your physician’s instructions be followed carefully. The quality of the preparation can affect the physician’s ability to detect abnormalities in the colon. Any solid material retained in the colon may prolong the procedure or make it necessary to repeat the examination on another day.

As with all procedures it is important to advise the surgeon of all medication, vitamins and dietary supplements you are taking. Some dosages may need to be adjusted or avoided completely for a few days prior to the procedure. All allergies must be discussed with the physician or nurse as well. If you have a medical condition, such as diabetes, heart or lung disease that may require special attention during the procedure, discuss this with your physician.

When you arrive at the endoscopy center, one of our patient service coordinators will register you for your procedure. Your demographics and insurance information will be reviewed as well as your patient rights and responsibilities and privacy policy (link). The various consents which require your signature will be reviewed (link). You will be asked to change into a gown. A registered nurse or an anesthesiologist will review your medical history and current medication use. Updating this information will make the procedure safe for you. Please be prepared to review your health history at this time. Bring a list of medications and drug allergies, if necessary. Please inform your physician if you have any loose dental work, or easily removed bridges.

All procedures are performed with the assistance of a board certified anesthesiologist who will monitor you before, during and after the procedure. You will be given an intravenous medication that will make most patients fall asleep. Your blood pressure, pulse rate, and oxygen saturation will be monitored before, during and after the exam.

During the procedure

For Upper EUS: You may have your throat sprayed with a local anesthetic before the test begins. You will lie on your side in a comfortable position as the endoscope is gently passed through your mouth and into your esophagus, stomach and duodenum. The endoscope does not interfere with your breathing. Most patients fall asleep during the procedure. The procedure usually lasts 30-45 minutes.

For Lower EUS: you will be positioned on your side and the colonoscope will be gently passed through your rectum and into your colon (large intestine). The physician will put air into your colon to help visualize the lining. Most sleep through the entire procedure, which lasts 30-45 minutes.

Following your procedure

you will be monitored by a registered nurse in the recovery area until the effects of the sedatives have worn off. Most patients recover in 30-45 minutes. Your throat may be a little sore for a day or two and you may feel bloated or nauseous immediately after the procedure because of the air that is introduced into your stomach during the examination. You will be able to resume your diet and take your routine medication after you leave the endoscopy center, unless otherwise instructed.

Results of any tissue samples take approximately 5 days to return. You will meet with your doctor after the procedure and receive preliminary results and specific instructions prior to discharge. Your escort or caretaker is expected to be available to receive these instructions as well and must sign you out of the facility (escort policy).

The sedation used during your exam impairs judgment, memory, and equilibrium. Do not drive, operate machinery, make critical decisions, drink alcoholic beverages, or do activities that require coordination or balance for 24 hours.

  • If given medication for pain, take it, as instructed, so your pain is not overwhelming.
  • You may experience a sore throat for 24 to 48 hours. You may use throat lozenges or gargle with warm water to relieve the discomfort.
  • Because air was put into your stomach during the procedure, you may experience some belching.

Potential Complications: When performed by a knowledgeable and competent physician, an Endoscopy Ultrasound (EUS) is a very low risk procedure. Complications from EUS without the fine needle aspiration are very rarely (less than 1 in 1200). When an FNA is performed complications occur more often .5-1%) Bleeding or perforation (a hole or tear in the lining of the gastrointestinal tract) may occur. Other risks include a reaction to medication, irritation at the site of the injection, or complications related to other medical problems that you may already have.

  • A Perforation: Passage of the instrument may result in an injury to the gastrointestinal tract wall with possible leakage of gastrointestinal contents into the body cavity. If this occurs, surgery to close the leak and/or drain the region is usually required.
  • Bleeding: Bleeding, if it occurs, is usually a complication of FNA. Management of this complication may occur immediately during the procedure or may occur within a few days and consist only of careful observation, a repeat endoscopy, may require blood transfusions or possibly a surgical operation.
  • Medication Phlebitis: Medications used for sedation may irritate the vein in which they are injected. This causes a red, painful swelling of the vein and surrounding tissue. The area could become infected. Discomfort in the area may persist for several weeks to several months.
  • Conscious Sedation Medication and Pregnancy: There are risks involved with Anesthesia, especially as it relates to a pregnancy. If there is a question that a pregnancy is possible, a urine pregnancy test will be performed prior to the procedure. If you are breast feeding, do not breast feed for 48 hours after the procedure or you may speak with your obstetrician/gynecologist for more specific instructions.
  • Damage to teeth or dental work is not common, but may occur. This includes but is not limited to; cracking, chipping or complete loss of teeth as well as damage to prosthetics including bridges, implants, caps, or crowns.
  • Other Risks: Include drug reactions and complications from other diseases you may already have. Instrument failure and death are extremely rare but remain remote possibilities.


Although complications after Endoscopic Ultrasound are rare it is important for you to recognize early signs of any possible complication. Go directly to the emergency room and contact your physician if you notice any of the following:

  • Chills and/or fever over 101
  • Persistent vomiting or vomiting with blood/nasal regurgitation
  • Severe abdominal pain, other than gas cramps
  • Severe chest pain
  • Black, tarry stools

Please be informed that an Endoscopic Ultrasonography is never 100% accurate. After the procedure, if you should develop any new or recurrent gastrointestinal signs or symptoms, immediately bring it to the attention of your Physician.

There are alternatives to Endoscopic Ultrasonography. Although gastrointestinal endoscopy is an extremely safe and effective means of examining the gastrointestinal tract, it is not 100 percent accurate in diagnosis. In a small percentage of cases, a failure of diagnosis or misdiagnosis may result. Other diagnostic or therapeutic procedures, such as medical treatment, x-ray and surgery are available. Another option is to choose no diagnostic studies and/or treatment. Your physician will be happy to discuss these options with you.

If you have any questions, please contact your physician and your doctor will be happy to answer any questions that you may have.