A disposable undergarment is disclosed. The undergarment includes a chassis and an absorbent core assembly. The chassis includes a front section, a crotch section and a rear section. The absorbent core is located in the crotch section, with portions of it extending into the front and rear sections. A large plurality of closely spaced elastic threads extends across the full width of the undergarment in the front and rear sections. A large plurality of closely spaced elastic threads extends across the full width of the undergarment in portions of the crotch section adjacent the front and rear sections. The elastic threads are broken in the areas of the core assembly. The core assembly includes a first section of a slow acting but high absorbency SAP in pockets thereof and an underlying second section of a fast acting by lower absorbency SAP in pockets thereof.