A discharge muffler for a fluid pump is formed by a cowling and a muffler insert configured to be removably inserted into a muffler receptacle of the cowling. The muffler insert includes a muffler inlet, a muffler outlet, and a plurality of muffler walls. The pump includes a pumping stage, a motor, and a drive shaft coupled between the pumping stage and the motor. When the muffler insert is inserted into the muffler receptacle, the muffler inlet communicates with the pumping stage, and the cowling and the muffler insert cooperatively define the discharge muffler. The discharge muffler is configured or effective to suppress noise generated by fluid discharged from the pumping stage.