Is It Haram to Urinate Standing Up?
Question

What is the Shar’i ruling regarding standing while urinating? There is a hot debate here regarding this. While some claim that it is permissible, others claim it is haram. Their argument is that there is a hadith in which ‘Aishah says that “whoever tells you that the Prophet urinated while standing, do not believe him.” Please clarify the issue.
Praise be to Allah.It is not haram for a man to urinate standing up , but it is Sunnah for him to urinate sitting down, because `Aishah (may Allah be pleased with her) said: “Whoever tells you that the Prophet (peace and blessings of Allah be upon him) used to urinate standing up , do not believe him. He only ever used to urinate sitting down.” (Narrated by al-Tirmidhi, al-Taharah, 12; he said, this is the most sahih report on this topic. It was also classed as sahih by al-Albani in Sahih Sunan al-Tirmidhi, no. 11). And because this is more concealing, and it reduces the risk of any drops of urine splashing up onto him . 
`Umar, Ibn `Umar and Zayd ibn Thabit (may Allah be pleased with them) narrated that it is allowed to urinate standing up on the condition that there is no risk of drops of urine splashing onto one’s body or clothes, and that one does not expose one's `awrah. 
Al-Bukhari and Muslim narrated from Hudhayfah (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) came to a garden belonging to some people, and urinated standing up . There is no contradiction between this and the hadith of `Aishah (may Allah be pleased with her), because it is possible that the Prophet (peace and blessings of Allah be upon him) did that because he was in a place where he was unable to sit down, or he did that to show the people that it is not haram. This does not contradict the basic principle mentioned by `Aishah (may Allah be pleased with her), that he (peace and blessings of Allah be upon him) urinated sitting down, because it is Sunnah, it is not something obligatory which it is forbidden to go against.
And Allah knows best.