Menstrual Periods

Bukhari :: Book 1 :: Volume 6 :: Hadith 324

Narrated 'Aisha:

(the wife of the Prophet) Um Habiba got bleeding in between the periods for seven years. She asked Allah's Apostle about it. He ordered her to take a bath (after the termination of actual periods) and added that it was (from) a blood vessel. So she used to take a bath for every prayer.