Which fingers are used for cleaning oneself after defecation, or is the entire left hand used?

A Muslim should use his left hand to remove impurities, whether from urine or feces, and avoid using his right hand for this, due to what was narrated from the Prophet, may Allah's prayers and peace be upon him: "None of you should hold his penis with his right hand while urinating, nor should he clean himself with his right hand after defecating."