The study of dietary supplement (biologically active additive) Prolit in 20 patients and 20 controls (mean age 44.0 +/- 13.8 years) hospitalized for urolithiasis, uncomplicated renal colic proved that Prolit use in combined therapy of urolithiasis effectively relieves pain syndrome (renal colic) and prevents its recurrence. Prolit has a pronounced anti-inflammatory and spasmolytic effects which prevent attacks of acute (chronic) pyelonephritis. Combined treatment of urolithiasis with Prolit addition has one more advantage over conventional therapy in evacuation of the concrements and elimination of urostasis, especially in small concrements (up to 1 cm) in the ureter.