A catheter (200) for insertion into a hollow viscus of a subject, comprising:a drainage opening (204) and an instillation opening at a distal end； an inletport (209) at a proximal end for instilling a fluid； an outlet port (205) at theproximal end for draining fluid from the viscus； a drainage channel (201) connectingthe drainage opening to the outlet port； an instillation channel (211) connectingthe inlet port to the instillation opening； a valve (223) proximate the drainagechannel at the distal end for closing it against the entry of fluid from the viscus；a valve control port (220) at the proximal end for receiving a control fluid underpressure； and a control channel (222) connecting the valve control port to thevalve such that the valve is responsive to admitted control fluid under pressureto close itself.
