The present invention relates to an apparatus for performing peritoneal dialysis, the apparatus comprising means for delivering dialysis fluid to the peritoneal cavity of a patient, a measurement device for measuring the fluid pressure of the delivered dialysis fluid and/or the fluid pressure in the peritoneal cavity, i. e. the intraperitoneal pressure and/or any pressure related thereto, and a control unit operably connected to said means and the measurement device, wherein the control unit is configured to effect an inflow or outflow phase encompassing a series of fill-and-measurement or drain-and-measurement steps, each step comprising delivering a predetermined quantity of dialysis fluid to the peritoneal cavity or draining a predetermined quantity of dialysis fluid from the peritoneal cavity and subsequently measuring and recording a pressure value.