Washing the Necessary Parts
Question :

If one thought that he was washing the necessary parts of the wudhu, but years later realized that he had been missing some of them, is it obligatory on him to repeat all of those prayers that he performed with this wudhu?

Answer :

If one doubts the correctness of the wudhu but at the same it is probable that he washed the necessary parts without intending to do so, then he can assume that the wudhu is in order and he does not need to repeat the prayer. If he knows that he did not wash a necessary part of the wudhu, then it is invalid and he must repeat the prayers that he performed with such wudhu.

Doubts in Washing Properly
Question :

During wudhu, I always become doubtful as to whether I am doing the washing properly e.g. whether or not I am wiping my arms in a manner where it is reaching everywhere, which leads me to be very meticulous in my wudhu. May I ignore this doubt?

Answer :

If the doubt is conventionally normal, and not a type of waswasah, one should pay attention to it, and therefore wash until he is certain that during the washings the water has reached all parts of the face or arm. If the doubt is a type of waswasah, then one should ignore it.