An endoscopic ultrasound (or EUS) is a procedure to examine the inside of the digestive tract. This is done by using a thin, flexible tube with a camera and light on the end, as well as an ultrasound probe that sends out sound waves to produce images of your organs, tissues and blood vessels. During the EUS, your endoscopist may also perform fine-needle aspiration or biopsy, which is done to remove a small sample of fluid or tissue. This sample goes to a pathology lab to be examined further for signs of disease, including abnormal or cancer cells. Before the EUS, your healthcare provider will discuss with you any changes in medications (such as blood thinners) that may need to be held. You should not eat or drink for eight hours prior to the test. The procedure typically lasts no longer than 30 minutes. You'll be under sedation while the procedure takes place. You shouldn't feel any pain during or after the procedure. Upon awakening, you'll be in the recovery area until you're ready to be discharged home with your driver. Prior to leaving, your endoscopist will be able to discuss the findings of the exam.