A colonoscopy and upper endoscopy (EGD) is a combined procedure that involves the insertion of one long, flexible camera into the rectum and another into the mouth. These cameras allows the doctor to view the inside of the large intestine, rectum, and part of the small intestine from the lower end and the esophagus and throat from the upper end. This includes a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum. This procedure involves sedation and allows the doctor to check for changes or blockages that may be present in either location.