According to some embodiments of the invention there is provided a colon cleaning system comprising: a working channel, a vacuum source, a separate vacuum pipe provided alongside the working channel, and a sensor positioned at a conduit connected externally to the working channel, the sensor configured for providing an indication related to pressure within at least a segment of the working channel. In some embodiments, the system comprises a controller configured for controlling one or more parameters of a vacuum induced in the separate vacuum pipe, the parameter determined according to the pressure related indication provided by the sensor.