since the entire check valve 24 and outlet assembly 18 are located outside the human body any fluid backflow will be completely prevented from reentering the body by preventing the flow from reentering the body in this manner the present invention also prevents the potential for introducing harmful organisms or infectious material into the patient further since the check valve 24 is placed at a point in the catheter 10 where the diameter is slightly larger it is less likely to become clogged the likelihood of clogging is also reduced by placing the check valve 24 further down the catheter 10 where the pressure of the out flow is higher and more likely to dislodge potential clogs such as accumulated crystal materials in the patient 39 s urine another important feature provided in the present invention is the positive locking assembly 28 provided on the outlet end 18 of the catheter 10 in the preferred embodiment female threads 30 are provided within the inner surface of the catheter 10 wall the female threads 30 are provided to engage corresponding male threads not shown on any attachments connected thereto preventing accidental disengagement of the collection assembly from the outlet end 18 of the catheter 10 this.