Should a Muslim make Istinja''

Q 1: Is Istinja' (cleansing the private parts with water after urination or defecation) part of performing Wudu' (ablution) for Salah (Prayer) or is it obligatory only upon defecation? I would like to know this point in detail as it appears to me that Istinja is not a part of Wudu'. Can I begin with washing my face and then complete making Wudu' after getting up in the morning without performing Istinja' because I slept in a state of minor ritual purity? This means that I will wash my face in the morning and complete making Wudu' without going to the toilet.

A: All Praise be to Allah Alone and peace and blessings be upon His Messenger, his family and Companions. To commence: Istinja' should be performed before Wudu' through washing the traces of what comes out of the private parts whether urine, excrement or the like. Istinja' is not part of Wudu' as Wudu' begins with washing hands up to the wristbone and Madmadah (rinsing the mouth) and ends with washing feet. He who gets up without urinating or defecating can perform Wudu' by washing his hands up to the wristbone, rinsing his mouth, sniffing water and then forcing it out, washing his face and hands up to the elbows, wiping over his head along with his ears and washing his feet up to the anklebone. He is not required to perform Istinja'.