Musannaf Ibn Abi Shayba 3:5695

Abu Bakr narrated to us, he said: Jarir narrated to us, from Abd al-Aziz ibn Rufay’, from ‘Ata’, from Ibn ‘Abbas, he said: The woman suffering from prolonged non-menstrual bleeding (mustahada) shall delay the Dhuhr prayer and hasten the Asr prayer, and combine them, and perform ghusl once. And she shall delay the Maghrib prayer and hasten the Isha prayer, and perform ghusl once. And she shall perform ghusl for the Fajr prayer.