Abu Dawud Book 1, Hadith Number 294.
Chapter : A person who is sexually defiled is permitted to eat anything before washing.
Narated By ‘Aisha, Ummul Mu’minin : A woman had a prolonged flow of blood in the time of the Apostle of Allah (PBUH). She was commanded to advance the afternoon prayer and delay the noon prayer, and to take a bath for them only once; and to delay the sunset prayer and advance the night prayer and to take a bath only once for them; and to take a bath separately for the dawn prayer.
I (Shu’bah) asked Abdur Rahman: (Is it) from the Prophet (PBUH)? I do not report to you anything except from the Prophet (PBUH).