It is narrated from Sayyidah Aishah (may Allah be pleased with her) that Fatimah bint Abi Hubaysh (may Allah be pleased with her) said: O Messenger of Allah! I suffer from istihadah (prolonged bleeding) and the blood does not stop for me. He (peace and blessings be upon him) said: "Leave the prayer during the days of your menstruation; then, when the days of your menstruation have passed, take a ritual bath (ghusl) and perform ablution (wudu) for every prayer."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21263