An insert is rotatable relative to a housing to transition the stopcock between different operational states with various different ports being open or closed. The insert includes a manifold shaft which resides within a hollow core of a hub of the housing. The openings are brought into and out of alignment with ports in the housing to cause the stopcock to transition between operational states with two or more of the ports being open or all of the ports being closed. The manifold shaft and hollow core include either detent slots or detent ribs thereon which coact together to cause the ribs to reside within the slots when the insert is rotated to one of the desired operational states, and for the ribs and slots to be out of alignment when outside of one of the desired operational states. The stopcock thus tends to snap into desired operational states.
