The present invention relates to a device for determining the peritoneal pressure in the abdominal cavity of a patient and/or for determining the state of emptying of the abdominal cavity of a patient, wherein the device comprises at least one pump for delivering a dialysis solution into the abdominal cavity and at least one measuring device for measuring the pressure in the dialysis solution, wherein the device comprises at least one control unit which is configured in such a way that it controls the pump and the measuring device in such a way that, in order to obtain a first pressure measurement value, a first measurement of the pressure is carried out by the measuring device when the pump is stationary, after which the pump for delivering a partial volume of the overall volume of the dialysis solution flowing into the abdominal cavity is started up and the pump then stops and, thereafter, in order to obtain a second pressure measurement value, a second measurement of the pressure is carried out by the measuring device.