Endoscopes were originally used for observation and diagnosis, but are now also used in combination with other medical tools to perform medical procedures and treatments. Endoscopes are combined with a large variety of medical tools to allow the physician to perform procedures such as grasping, cutting, crushing, and removing diseased tissue; take samples of lesions; and excise polyps while observing a television monitor. There are now as many as 1,000 types of medical tools used in combination with endoscopes.