Abu Hurairah narrated that the Messenger of Allah (صلي الله عليه وسلم ) said: "Allah - the Exalted, Majestic is His mention - does not accept the prayer of one of you, when he commits Hadath until he performs Wudhu'." (Abu Dawud)
‘Hadath’ means anything that nullifies your Wudhu i.e. stool, passing wind, urine etc.
Abu Hurairah narrated that the Messenger of Allah (صلي الله عليه وسلم) said: "If one of you is praying, and he feels a movement in his behind, and he is not sure whether he broke his Wudu or not, then let him not leave until he hears a sound or smells something. (Abu Dawud)
Ali bin Talq reported that the Messenger of Allah (صلي الله عليه وسلم) said: "If one of you silently passes wind in the prayer, let him leave, perform the Wudü', and repeat the prayer." (Abu Dawud)
