Answered by Ustadh Tabraze Azam
Question: As-Salamu Alaykum, would it be permissible to perform wudu (in the sink) then perform istinja and the rest of the ghusl in the shower – if impurities (minor) exit after performing or during wudu and the person is going to prayer later, can they continue and perform wudu before they begin the prayer?
Answer: Wa alaikum assalam wa rahmatullah,
I pray that you are in the best of health and faith, insha’Allah.
[1] Performing the ablution (wudu) first would be contrary to the sunna. As the sunna is to first clean your private parts, then to perform a complete wudu, and then to take the bath (ghusl).
[2] If you perform a ghusl after the wudu, then you are in a state of purification. You do not need to repeat anything.
[Shurunbulali, Maraqi al-Falah]
And Allah alone gives success.
Wassalam,
Tabraze Azam