Ok. So I watched a couple of videos about urine sin. I was wandering, if I wiped after I went to the toilet, and then after I went out, a drop of urine fell on my underwear, would that be considered as the urine sin? Or is it just that you must wipe after you go toilet.
Also, if there is some impurity after defecating, but you have wiped with tissue paper (not used water though) is that fine?