Endoscopic ultrasound (EUS) is a minimally invasive procedure to assess digestive (gastrointestinal) and lung diseases. A special endoscope uses high-frequency sound waves to produce detailed images of the lining and walls of your digestive tract and chest, nearby organs such as the pancreas and liver, and lymph nodes. Endoscopic ultrasound does not hurt. In fact, most patients suggest they do not remember it because of the intravenous (IV) sedative they receive. It does not take long to recover from an endoscopic ultrasound. Some patients experience mild and temporary stomach cramping or bloating after the procedure.