A system for distending body tissue cavities of subjects by continuous flow irrigation during endoscopic procedures, the system comprising: - and endoscope instrument; - a variable speed positive displacement inflow pump; - an inflow tube for connecting avariable speed positive displacement in flow pump with the inflow part of the endoscope; - an inflow pressure transducer; - a waste fluid collecting container - a waste fluid tube; - an active inflow pressure pulsation dampening means; a fluid source reservoir for containing a non viscous physiologic fluid; a fluid supply tube connecting the fluid source reservoir to an inlet end of the variable speed positive displacement inflow pump and an outlet end of the said inflow pump being connected to an inflow port of the endoscope instrument through the inflow tube for pumping the fluid at a controlled flow rate into the cavity; the inflow pressure transducer being located anywhere in the inflow tube between the outlet end of the inflow pump and the inflow port of the endoscope instrument; and an outflow port of the endoscope instrument being connected to the waste fluid collecting container via the waste fluid tube, wherein the active inflow pressure pulsation dampening means is connected to the inflow tube for dampening the pressure pulsations inside the cavity created by the positive displacement inflow pump; and wherein the active inflow pressure pulsation dampening means comprises a single outlet syringe mechanism, the piston of the same being coupled synchronously to the positive displacement inflow pump through a coupling means and a single outlet end of the said syringe mechanism being connected to the inflow tube. - and endoscope instrument; - a variable speed positive displacement inflow pump; - an inflow tube for connecting avariable speed positive displacement in flow pump with the inflow part of the endoscope; - an inflow pressure transducer; - a waste fluid collecting container - a waste fluid tube; - an active inflow pressure pulsation dampening means; a fluid source reservoir for containing a non viscous physiologic fluid; a fluid supply tube connecting the fluid source reservoir to an inlet end of the variable speed positive displacement inflow pump and an outlet end of the said inflow pump being connected to an inflow port of the endoscope instrument through the inflow tube for pumping the fluid at a controlled flow rate into the cavity; the inflow pressure transducer being located anywhere in the inflow tube between the outlet end of the inflow pump and the inflow port of the endoscope instrument; and an outflow port of the endoscope instrument being connected to the waste fluid collecting container via the waste fluid tube, wherein the active inflow pressure pulsation dampening means is connected to the inflow tube for dampening the pressure pulsations inside the cavity created by the positive displacement inflow pump; and wherein the active inflow pressure pulsation dampening means comprises a single outlet syringe mechanism, the piston of the same being coupled synchronously to the positive displacement inflow pump through a coupling means and a single outlet end of the said syringe mechanism being connected to the inflow tube.