Sahih Bukhari | Volume 1 | Hadith Number 137

Narrated by Abu Huraira
Allah's Apostle said, "The prayer of a person who does ,Hadath (passes, urine, stool or wind) is not accepted till he performs (repeats) the ablution." A person from Hadaramout asked Abu Huraira, "What is 'Hadath'?" Abu Huraira replied, "'Hadath' means the passing of wind from the anus."