Abstract: A check valve between a catheter and a urine collection bag for an incontinent person must pass urine in the forward direction without significant head and must be free of back leakage to prevent infection. This valve has a rigid body so that the elastomeric sealing member mounted therein is not disturbed by the wearer's clothing. The sealing member has a pair of flat, parallel, normally spaced apart, sealing leaves integrally joined together along their lateral edges by webs to define a flat tube having a flat normally open passage therethrough. Means are provided for pressing on the lateral edges of the leaves for forcing the edges of the passage closed. The leaves are thin, soft elastomer, and the side edges are free to deflect laterally so that urine will pass forwardly through the valve in drop-wise fashion, and the valve can also handle appreciable flow rates. Back pressure on the valve urges it closed. Preferably the means holding the valves leaves together are clips free from the rigid body.