An endoscopic ultrasound is used to diagnose and determine the proper course of treatment for certain digestive (gastrointestinal) diseases.

It uses a special tool called an endoscope with high-frequency sound waves to provide images of the lining and walls of the area of concern. During the procedure, your doctor also can take a biopsy of tissue and fluid to further analyze the area.

An endoscopic ultrasound is an important tool when diagnosing and treating esophageal, gastric, pancreatic and bile duct cancers. It also can be used to diagnose and help in treatment planning for Barrett’s esophagus, neuroendocrine tumors, pancreatitis and pancreatic cysts, bile duct stones, lymphoma and sarcoidosis.

“An endoscopic ultrasound is very important when surgery is needed to remove certain health concerns in your digestive tract because it allows us to pinpoint where the problem is,” said Dr. Sabo Tanimu, gastroenterologist with Marshfield Clinic Health System, who is trained to provide the procedure. “Without it, a surgeon may be forced to rely only on radiology scans or exploratory surgery in order to find and fix the problem.”

It also can help determine the stage of cancer and if it has spread to the surrounding lymph nodes or organs, both of which can be important in the treatment of cancer.

How does an endoscopic ultrasound work?

The endoscope looks like a thin and flexible tube. Your doctor will pass it through your mouth and throat in order to access your digestive tract.

Inside of the tube is an ultrasound that produces sound waves to create an image, similar to an ultrasound image you would see during pregnancy.

Depending on why the patient needs the procedure, a small needle can also be passed through the tube to collect tissue or fluids for the biopsy.

Patients typically need to fast and stop taking blood thinners before an endoscopic ultrasound. The procedure typically takes about an hour and patients are able to leave that day. To help you relax during the procedure, your doctor will give you some medicine. For this reason, you will need to bring someone to drive you home.

“While this procedure sounds like a big deal, the human body is able to handle it really well,” Dr. Tanimu said. “The procedure is typically regarded as safe with the biggest risk being the biopsy where bleeding and infection can happen.”

For more information about endoscopic ultrasounds, talk to your doctor.