Sayyidah Umm Habibah bint Jahsh (may Allah be pleased with her) said: I suffered from istihadah (non-menstrual bleeding) for seven years, and I complained about it to the Messenger of Allah (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said: "This is not menstruation; rather, it is (the flow of) a vein, so perform the ritual bath (ghusl)." So she used to take a ritual bath at the time of every prayer, and she would bathe in a large tub and see the yellowness of the blood in the tub.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20920