endostome

n. [ Endo- + -scope. ] (Med.) An instrument for examining the interior of the body, consisting of a flexible tube with lenses and optical fibers permitting illumination of the interior site to be inspected, and visualization of the interior site from outside the body; it often has small surgical instruments attached to the end and manipulable from the outside, permitting biopsy or surgery. It is used as a non-invasive or minimally invasive tool for diagnosis or treatment, especially in organs having an external opening such as the rectum, the urethra, and the bladder. [ 1913 Webster +PJC ]