Duodenoscopes are used for endoscopic examination and intervention in the duodenum, which is the first part of the small intestine. These endoscopes are specifically designed for procedures involving the duodenum, and they are commonly used in the fields of gastroenterology and gastrointestinal surgery. Duodenoscopes are flexible instruments that can be advanced through the esophagus into the stomach and then into the duodenum for diagnostic and therapeutic purposes.