What is the ruling on cleaning oneself with the hand, and is the method of using water pressure sufficient instead of using it?

Istinja' (purification after defecation/urination) is obligatory. It involves removing impurity with water or removing its effect with a stone or similar object. Water is not exclusively required; the important thing is to purify the area from impurity. If the impurity itself and its trace are removed by pouring water and allowing it to flow, without using the hand, then the istinja' is sufficient. This is based on the jurists' saying that if someone used for istijmar (purification with stones) something that is forbidden by religious law, yet purified the area, it is still sufficient, because the impurity has been removed.