Abstract: A disposable waterproof encasement for an absorbent sanitary pad may be releasably secured to an undergarment to convert an everyday undergarment into a sanitary panty or stress incontinence garment. Preferably, the encasement is secured to the panty with the Velcro-type fasteners. The encasement includes a waterproof back and a waterproof marginal front portion secured to the marginal portion of the back to form a water-tight fold. The marginal front portion forms an opening to expose the absorbent pad. The encasement may include an elongated strap bridging the central portion of the opening for retaining the absorbent pad within the encasement. One end portion of the strap may be releasably secured to the front marginal portion to facilitate insertion and removal of the absorbent pad. To ease removing the absorbent pad, the encasement may include an elasticized rubber pad.