What if a person did their wudhu (ablution) but then doubted about its correctness or the correctness of some part of it, would it be considered valid?
With respect to the issue of wudhu (ablution), if the person doubts about washing or wiping after his or her wudhu is over and he or she is considered to have already completed the entire act (e.g. they are now doing something else or have left the place of wudhu), then he or she should not pay attention to their doubt.
if a person doubts washing or wiping a body part while still in the process of performing wudhu (i.e. moisture from the previous part(s) remains and muwalat (succession) exists), he or she should wash or wipe that part again and the parts that follow to maintain tarteeb (order). However, if the part preceding the doubted act has dried up due to lapsed time (i.e. succession is not maintained), he or she should perform their wudhu from the beginning. However, note that wiping (massh) must always be on a dry surface (skin).