A medical device sheath that includes a relatively inelastic body having a proximal end longitudinally separated from a distal end and defining a first lumen, an aperture located at the proximal end in fluid communication with the lumen and configured to admit an elongate endoscope body into the first lumen, and a transparent tip located longitudinally adjacent to an endoscope lens when the elongate endoscope body is located within the first lumen. The endoscope sheath may also include an elongate secondary tube defining a secondary lumen. A method of using the medical device sheath is also described.