Single balloon deep enteroscopy is an endoscopic procedure used to examine the stomach, lining of the esophagus and most frequently the small intestine to diagnose and treat diseases found in those areas. A small endoscope with a overtube and balloon on the end is inserted down the throat where the balloon can be inflated and deflated to allow the endoscope to reach deep into the small intestine. This procedure is typically performed when patients have problems with their small intestine such as bleeding, narrowing, polyps, inflammation or tumors within the small intestine and the doctor needs to view the area for treatment.