An endoscope sheath comprising: a relatively inelastic sheath body, the relatively inelastic sheath body having a proximal sheath end longitudinally separated from a distal sheath end and defining a sheath lumen, a scope aperture located at the proximal sheath end in fluid communication with the sheath lumen and configured to admit an elongate endoscope body into the sheath lumen, a sheath tip located at the distal sheath end, an evacuation fitting in fluid communication with the sheath lumen and configured for selective removal of fluid from the sheath lumen such that the sheath body is suction-fit to the elongate endoscope body, the evacuation fitting including a valve being configured to prevent fluid from passing back into the sheath lumen; characterised by at least a portion of the sheath tip being configured to permit energy transmission therethrough and being located longitudinally adjacent to an endoscope lens of the elongate endoscope body when the elongated endoscope body is located within the sheath lumen, an elongate secondary tube having a proximal secondary tube end longitudinally separated from a distal secondary tube end and defining a secondary lumen, at least a portion of the secondary lumen extending substantially parallel to the sheath lumen, the elongate secondary tube being secured to an outer surface of the sheath body and including a secondary tube fitting located at the proximal secondary tube end to allow the user to access the secondary lumen and the distal secondary tube end from outside the patient's body, the valve having a pilot balloon that is coupled thereto and wherein the state of the pilot balloon being configured to indicate the pressure in the sheath lumen. a relatively inelastic sheath body, the relatively inelastic sheath body having a proximal sheath end longitudinally separated from a distal sheath end and defining a sheath lumen, a scope aperture located at the proximal sheath end in fluid communication with the sheath lumen and configured to admit an elongate endoscope body into the sheath lumen, a sheath tip located at the distal sheath end, an evacuation fitting in fluid communication with the sheath lumen and configured for selective removal of fluid from the sheath lumen such that the sheath body is suction-fit to the elongate endoscope body, the evacuation fitting including a valve being configured to prevent fluid from passing back into the sheath lumen; characterised by at least a portion of the sheath tip being configured to permit energy transmission therethrough and being located longitudinally adjacent to an endoscope lens of the elongate endoscope body when the elongated endoscope body is located within the sheath lumen, an elongate secondary tube having a proximal secondary tube end longitudinally separated from a distal secondary tube end and defining a secondary lumen, at least a portion of the secondary lumen extending substantially parallel to the sheath lumen, the elongate secondary tube being secured to an outer surface of the sheath body and including a secondary tube fitting located at the proximal secondary tube end to allow the user to access the secondary lumen and the distal secondary tube end from outside the patient's body, the valve having a pilot balloon that is coupled thereto and wherein the state of the pilot balloon being configured to indicate the pressure in the sheath lumen.