An improved drain unclogging device of the type having a drain bladder for sealing in the drain and a water source interface in fluid communication with the drain bladder and fluidly interfacing with a water source to provide high pressure water to and exit from the drain bladder to unclog the drain. The improvement includes a sliding bladder restrictor that is movable over the drain bladder and restricts a portion of the drain bladder that remains outside the drain to prevent distortion of that portion of the drain bladder that would reduce pressure of the high pressure water that is exiting the drain bladder and unclogging the drain.