A sheath assembly for an endoscope includes an elongate tubular body and a plug. The endoscope has a handle portion and a scope portion extending therefrom to a tip. The body includes first (40) and second (42) wall sections and extends along a longitudinal axis between first and second distal openings located at distal and proximal ends thereof, respectively. The first wall section (40) extends radially about the longitudinal axis to define a scope lumen (44). The scope portion is receivable in the scope lumen with the distal and proximal ends. The second wall section (42) extends radially about a portion of the first wall section (40) and longitudinally between second distal and proximal end openings. The first and second wall sections define an integral suction lumen (50) in fluid communication with a first source of negative pressure. The plug is mated with the distal end opening and includes a lens surface through which energy is transmissible.