An endoscopic ultrasound (EUS) involves passing a thin tube (endoscope) either through the mouth, down the esophagus and into the stomach or into the rectum. The tube has an ultrasound device, a light and a tiny camera. Ultrasound uses sound waves to create pictures of internal parts of the body. EUS allows your doctor to see the tissue layers beneath the surface of the GI tract and also nearby organs and structures.
For parts of the body that are harder to see with an ultrasound from the outside, doctors use ultrasound devices that go inside the body.
With EUS, your doctor can check for inflammation, scarring, cysts and noncancerous (benign) and cancerous (malignant) tumors. Your doctor may also take a sample of your cells (biopsy) or fluids during the EUS.