A valve for a urostomy appliance comprising a body with an inlet 14 and outlet 16 connected by a flow path and a blocking member 30, the blocking member is supported by the body and moveable between a closed and open position. The inlet is shaped such that as the blocking member is moved from an initially open position to a fully open position, the rate of change of a permitted flow rate through the valve increases with non-linear proportionality as the blocking moves. The inlet is shaped and provided as a tear-drop, egg/oval, trapezoidal pentagonal or kite shaped. The body may comprise a guide channel. The blocking member may comprise a depression 40. The blocking member may be rotatably moveable between the closed and open position. A combination of the valve and urostomy appliance are also provided.
