Ultrasound findings: left kidney 106×66mm, with enlarged measurements, disorganized intrarenal structures, fancy separation of the collecting system, maximum spacing 29mm, no stone occupancy. The right kidney was 93×54 mm, with normal morphology, intact peritoneum, clear intrarenal structures, and no stones, fluid and occupancy in the collecting system. The upper ureter was not significantly dilated bilaterally. The bladder was moderately full with a smooth and intact wall, and no significant abnormal echogenicity was seen within it. The prostate gland was 30×20×26 mm, with normal morphology, intact envelope, and uniform echogenicity of the gland. 1. no stones are seen why there is also fluid 2. in this case is it necessary to check again for stones 3. occult blood 4+ 4. do I need to take lithotriptic drugs?