Once your stool leaves the body, it ends up in the toilet (or a hole in the ground if you're in a more primitive or wild environment), and is (hopefully) flushed away.
Once sezinyawo zakho ishiya umzimba, ugcina in the toilet (noma imbobo emhlabathini uma uku endaweni bakudala more noma zasendle), futhi (ngethemba) ezibomvana away.