What are the conditions for istijmar according to the four schools of Islamic jurisprudence, and what is the view of other schools regarding the obligation of istinja’ for women after urinating?

The jurists agree that istijmar (cleansing with stones/solid objects) is not sufficient if the excreted matter goes beyond the exit point and spreads extensively; rather, ghusl (washing) becomes obligatory. Istijmar is a concession limited to cases where the affliction is widespread, and anything beyond that must be removed by washing.

Istijmar is sufficient for a woman for feces by agreement. As for urine:

Malikis: Istijmar is not sufficient for a woman's urine, whether she is a virgin or non-virgin, because it usually goes beyond the exit point. Shafi'is: For a virgin, it is sufficient to remove the substance of the impurity. As for a non-virgin, if it is confirmed that urine has reached the outer part of the vagina, istijmar is not sufficient; otherwise, it is sufficient, and washing is then recommended. Hanbalis: There are two views regarding a non-virgin; one is that istijmar is sufficient for her, and the other is that washing is obligatory.

The most preponderant view is that a woman is like a man in this regard, whether she is a virgin or non-virgin, and this is what some discerning scholars have chosen. She may perform istinjal (cleansing) with water or istijmar with stones, and combining both is more complete.