What is the ruling on one who performed wudu' but did not perform istinja', then prayed and completed 'Umrah?

Question:
He says: My sister, during her tawaf for 'Umrah, had a discharge. It was the time for the Maghrib prayer, so she performed wudu' but did not perform istinja', and she completed the 'Umrah. Is her action valid?

Answer:
If, after relieving himself, a person has used stones or rough towels to dry the exit, thereby drying the exit, then using stones (istijmar) is sufficient in place of istinja', and his wudu' is valid, if Allah wills. However, if he did not use stones and the trace of the discharge remains on him, then his wudu' is not valid.
He is required to perform istinja', repeat the wudu', and repeat the prayer he prayed or the tawaf he performed for 'Umrah. He must repeat the sa'y and repeat the shortening of the hair, because he performed a tawaf that was not valid, and 'Umrah is built upon the tawaf, which is its first act.
So the conclusion is that if he dried the exit with something that dries it of the trace of the discharge, which is istijmar, then this is sufficient. But if the trace remains and the ritual impurity remains, then his worship is not valid. He must use stones or perform istinja', perform wudu', and repeat the worship, whether it is the prayer or the tawaf. Yes.