Explanation:
Decrease in filtrate production due to an increase in hydrostatic pressure in the capsular space.
Since the stone is lodged into the ascending limp of nephron the urinre will not be able to empty into the distal convulated tubule. This will result in increased hydrostatic pressure in the capsular space and hence the filtration of blood will reduce, as the filtrate will not be allowed to move into the capsule. So the amount of filtrate will reduce.
