There is provided a method for controlling a flow of fluid in the vas deferens in order to obtain a controlled male contraception. The method comprises gently constricting (i.e., without substantially hampering the blood circulation in the tissue wall) at least one portion of the tissue wall to influence the flow vas deferens, and stimulating the constricted wall portion to cause contraction of the wall portion to further influence the flow in the vas deferens. The method can be used for restricting or stopping the flow in the vas deferens, or for actively moving the fluid in the vas deferens, with a low risk of injuring the organ.