A stent is a hollow tube made from metal or plastic that is placed in a bodily orifice to keep it open. Stents are commonly used in gastroenterology as support structures to keep the esophagus or bile ducts open. They also may be placed within the stomach, small bowel or colon. In most cases, placement of a stent is performed as a minimally invasive, endoscopic outpatient procedure with an overnight hospital stay. For most patients with esophageal or swallowing difficulties, for example, stent placement offers immediate and long lasting relief.