Abstract: A sheath device (1) suitable for endoscopic instruments (2) and comprising an elongated tubular member (4) having a proximal end (6), a distal open end (7), and at least one fluid channel (23). A flushing unit (5) is connected to the proximal end (6) of the tubular member (4) and comprises a proximal open end (8) suitable for receiving a first endoscopic instrument (2), a fluid inlet (16) in contact with said fluid channel (23), and a fluid outlet (17). The tubular member and the flushing unit together define a first interior guiding passage (10) for sheathing at least a part of said first endoscopic instrument (2). The connection between the tubular member (4) and the flushing unit (5) allows for axial rotation of the tubular member (4) in relation to the flushing unit (5).