According to a preferred embodiment of the present invention there is provided a stopcock including a housing element defining at least first, second and third ports, a handle element which is selectably positionable relative to the housing element, at least one fluid passageway communicating between at least two of the at least first, second and third ports, the at least one fluid passageway being selectably defined by at least one of the housing element and the handle element, the at least one fluid passageway being configured for enabling flushing an internal volume of at least one of the first, second and third ports by a fluid flow which does not flow entirely through the port whose internal volume is being flushed.