Tahaarat

Discharging semen after urinating

Q: I woke up and there was this whitish liquid that was inside. It hadn't come out but after I urinated got up and everything it hurt and I am quiet constipated but I didn't go to pass stool then or anytime before so should I consider it as wadi? The only time I went for stool was yesterday evening and later yesterday I went to the toilet put pressure but nothing come out.

Used water

Q: When one washes one's hands in a wash basin/sink, or makes wudhu in a wash basin/sink, there is almost always some splash back from the sink. Is this splash back considered najas (impure)?

Wet dream

Q: The underwear I had on I cant like really see any round patch on it so should I just consider my body paak and consider ghusl to not be fard?