Sorbent regeneration of peritoneal dialysate and use of small volume of dialysate for intermittent peritoneal dialysis (IPD) has been shown to be feasible. The present study compares the solute clearance (C) for urea (U) and creatinine (Cr) at varying flow rates in IPD and in recirculation peritoneal dialysis (RPD) utilizing Redy cartridge in ten dogs. Two silastic peritoneal catheters and one Sarns roller pump were used for RPD. CU was 12 +/- 2 ml/min (mean +/- 1SD),18 +/- 2 with IPD and 15 +/- 2,21 +/- 4 with RPD at flow rate of 66 and 100 ml/min, respectively, while CCr was 9 +/- 2,12 +/- 2 with IPD and 10 +/- 2, 13 +/- 3 with RPD. At increasing flow rates of 150,200 and 250 ml/min, CU was 27 +/- 3,31 +/- 4 and 32 +/- 6, and CCr was 17 +/- 2,20 +/- 3 and 22 +/- 3 with RPD. U and Cr were completely removed by the Redy. Glucose was not removed by the cartridge after initial saturation. Serum sodium concentration increased 2-3 mEq/l after 6 h of RPD. The data suggest that at comparable flow rates, RPD is relatively more efficient than IPD (p greater than 0.01). This may be due to continuous exchange across the peritoneal membrane in RPD. At high flow rate in RPD, solute removal is 2-3 times higher than the currently used IPD. RPD with Redy cartridge is mechanically simple, efficient, and may help reduce total peritoneal dialysis time.