A control system for supplying a fluid medium to an endoscopic apparatus is disclosed. The apparatus comprises an operation handle and an insertion member insertable within a body channel, wherein there is provided a protection sleeve adapted to cover at least a portion of the insertion member. The control system comprises a system control unit with a pump for supplying compressed air at least to the channel for inflating the sleeve. The system control unit is provided with a duct, which is in fluid communication with the pump. The duct comprises a first branch through which the compressed air from the pump passes to the sleeve and a second branch having exit to atmosphere, said second branch is provided with a controllable flow regulating means.