Abstract: A disposable diaper includes a water impervious envelope disposed adjacent to a diaper inner layer, an opening in the envelope positioned to substantially bisect a portion of the diaper wherein the opening is opposite the inner layer and provides a seal when the envelope is inverted. The envelope may be attached to the inner layer opposite the area of the bisected portion of the diaper. The seal may be an interlocking groove and ridge, adhesive or a tape strip. The diaper may include one or more outer layers. The envelope may provide a substantial moisture barrier for the diaper. The envelope opening may be frangibly accessible through an outer layer, for example a frangible zone in the outer layer.