Definition & Overview

An endoscopic ultrasound is a diagnostic procedure performed to obtain detailed images of the digestive tract and surrounding organs and tissues to evaluate abnormalities, confirm a diagnosis, or determine the extent of an existing medical problem.

Who Should Undergo and Expected Results

An endoscopic ultrasound is performed mainly to diagnose and determine the extent of the following medical conditions:

  • Cancer affecting any of the organs or those that surround the digestive tract, such as:
  1. Colon cancer
  2. Esophageal cancer
  3. Lung cancer
  4. Pancreatic cancer
  5. Stomach cancer
  6. Ampullary cancer
  7. Rectal cancer
  • Lymphoma
  • Neuroendocrine tumours
  • Pancreatitis
  • Pancreatic cysts
  • Bile duct stones
  • Rectal fistula
  • Fecal incontinence
  • Sarcoidosis
  • Barrett’s esophagus

Aside from diagnosing or detecting the abovementioned diseases, an endoscopic ultrasound can also be carried out to:

  • Evaluate any abnormalities, such as tumours, masses, and cysts
  • Evaluate the strength of the muscles of the lower digestive tract
  • Examine submucosal lesions that may be hiding in the intestinal wall
  • Determine the extent or stage of the cancer
  • Look for metastatic cancer
  • Obtain more information about malignant cells in order to create a more targeted treatment plan
  • Guide a physician in targeting the correct location where treatment needs to be administered
  • Drain out abnormal fluid buildups in the abdomen
  • Obtain a tissue biopsy

How is the Procedure Performed?

An endoscopic ultrasound is an outpatient procedure performed by a trained specialist. On the day of the procedure, the patient is:

  • Advised to fast hours before the test to ensure that the stomach is empty
  • Made to undergo an enema or consume a laxative to cleanse the bowels

To prepare for the procedure, the patient is:

  • Given an IV catheter where fluids and sedatives are delivered intravenously during the procedure
  • Monitored for vital signs and blood pressure and oxygen levels
  • Made to lie down on the left side and provided with a plastic bite block to protect the patient’s teeth if he accidentally bites the endoscope during the procedure

The doctor proceeds by inserting an endoscope either through the mouth or rectum, depending on which part of the digestive tract is to be examined. The endoscope, which has a camera attached to its end, is connected to a TV monitor allowing the doctor to observe the inside of the digestive tract and other organs during the procedure without making incisions.

The entire procedure typically takes between 20 and 45 minutes with most patients allowed to go home on the same day after the effects of the sedatives and anaesthetics have worn off.

Meanwhile, the recovery period takes only about 20 minutes to an hour. It is normal for patients to experience some soreness in the throat after the procedure, which is typically resolved with non-prescription anaesthetic-type throat lozenges.

Possible Risks and Complications

Although proven highly effective in determining the presence and extent of medical conditions affecting the digestive tract, an endoscopic ultrasound come with some risks, which include:

  • Infection
  • Bleeding
  • Perforation in the intestinal wall
  • Pancreatitis
  • Aspiration of the contents of the stomach into the lungs

It is important to note that these complications rarely occur. In fact, patients are not even given antibiotics to prevent infection. However, they are advised to watch out for unusual symptoms and to call their doctor right away should they experience the following:

  • Fever
  • Shortness of breath
  • Chest pain
  • Dark stool
  • Difficulty swallowing
  • Vomiting
  • Abdominal pain

Studies show that the risk of developing complications is higher in patients who had a biopsy taken and have an existing heart or lung disease. Some medications, such as blood thinners and medications prescribed for the treatment of diabetes and high blood pressure can also make the procedure riskier.


  • Giovannini M., Sun S. “Endoscopic Ultrasound.” Endosc Ultrasound. 2012 Apr-Jun; 1(1):1.

  • Koduru P., Suzuki R., Lakhtakia S. et al. “Role of endoscopic ultrasound in diagnosis and management of hepatocellular carcinoma.”

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