The invention relates to a catheter comprising a member (1) that can be inserted into a persons rectum, said member including a first rear opening (11) that communicates with a first passage (12) for discharging bodily fluids from an aperture (13) at the front end of the insertable member (1). The insertable member (1) includes an expandable ring element (14) communicating with a second rear opening (15) for connection to an inflation device. The catheter includes a probe (2) disposed at the front end of a connection pipe (4), which pipe is housed in the first passage (12) and connected at the rear end thereof to a device (3) for supplying a pressurised liquid, said probe (2) including several holes (21) in the rear portion thereof for projecting the liquid backwards, cleaning the colon and pushing the probe (2) forwards.
