It is proposed an assembly comprising a disposable waste content collection bag for collecting waste from an ostomy containment device comprising a stomal cover adapted to adjust to a topology of a skin of a user around a stoma, and a cap； wherein the bag is arranged outside the stomal cover in a folded configuration； the bag is adapted to be unfolded under the pressure of a bowel content； the bag is held in place by a cap adapted to fit over the stomal cover； and the cap includes a flexible portion adapted to protrude outwards when exposed to axial pressure exerted by bowel content, so that the user notices bulging flexible portion and is made aware of a need for evacuation.
