Sayyiduna Abu Salamah bin Abdur Rahman (may Allah be pleased with him) says: Zaynab bint Abi Salamah (may Allah be pleased with her) informed me that there was a woman who bled continuously, and she was the wife of Abdur Rahman bin Awf (may Allah be pleased with him). The Messenger of Allah (peace and blessings be upon him) ordered her: "She should perform a ritual bath (ghusl) for every prayer and pray."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1647