I am a student studying overseas, and I spend most of my day in the workplace. When I need to urinate, I do so standing because I feel that the toilet seat may be contaminated with impurity (najaasah), so I cannot bear to sit on it. I also try as much as possible to avoid getting any drops of urine on me. I also use toilet tissue to clean myself after urinating. What is the ruling on small drops of urine that may fall on my trousers after urinating whilst standing (despite taking precautions)? I hope you can explain whether the ruling is different if the person is certain that has happened as opposed to merely thinking that it may have happened. Is it sufficient to sprinkle water or wipe over what he thinks is the place where drops of urine fell? Does asking too many questions about this matter come under the heading of waswaas?