The mechanisms of the action of electrical stimulation of muscles are discussed. We believe that the principal cause for the good results obtained in cases of stress incontinence with electrical stimulation must be due to the formation of a better reflex in contraction of the muscles of the pelvic floor. This, however, envolves changes at the level of the spinal cord. By the help of stimulation the patient learns to use the urethral sphincter and secondary forces of retention in a better and a more proper way. The good results obtained in the treatment of some cases of nocturnal enuresis by anal plugs require yet another explanation. It can be considered that in nocturnal enuresis the unconscious inhibition of the reflex mechanism for emptying the bladder is not developed enough. From the experience we know that vigorous voluntary activation of the muscles of the pelvic floor inhibits the contraction of the detrusor muscle. In this way it is possible to depress the urging sensation to urinate. In the paper we have tried to demonstrate this mechanism objectively. On the basis of our findings we believe that the good results in treating nocturnal enuresis may be due to this mechanism of stimulation.