All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The blood poured forth is impure according to the view of the majority of the scholars of the four schools. Included in this [type of blood] is the woman’s blood outside her monthly periods as it resembles the blood poured forth when it comes out, and because it comes out from one of the two passages [front or back passage]. For instance, Al-Kaasaani stated the different types of impurities, and he included amongst them the woman’s blood outside her monthly menses. He said: '…and the blood of menses, and postpartum bleeding, and the blood outside the monthly periods, as all these types of bloods are impure.'
Allaah Knows best.