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 a control unit operably connected to said means and the measurement device, wherein the control unit is configured to effect an inflow phase encompassing a series of fill-and-measurement steps, each step comprising delivering a predetermined quantity of dialysis fluid to the peritoneal cavity and subsequently measuring and recording a pressure value, to establish a function of intraperitoneal pressure by added volume and to use this function to generate and output at least one therapy-related prediction or recommendation.
