A diaper comprises a rectangular disposable chassis assembly capable of absorbing and containing bodily wastes, including front, crotch and rear portions and a liquid-previous liner and liquid-impermeable barrier formed together about a liquid-absorbing core. A reusable elasticized cloth belt is removably retained by the chassis assembly, holding the diaper in place against the body during use. When fastened about a wearer, the belt provides a line of support extending transversely across the body of the core in the front portion of the chassis assembly corresponding to the lower abdominal region of the wearer. The belt cinches to snugly position the chassis assembly for absorbing discharged wastes. Preferably, the core contains a lower pledget with hydrogel that swells outwardly against the belt. Breathable elasticized leg cuffs extend along the side margins of the chassis assembly.