Is the brownish discharge that a woman sees after forty days of postpartum bleeding (nifas), and at the expected time of her menstrual period, considered menses (hayd) or irregular bleeding (istihada)?

Vaginal discharge (Kudra) after the fortieth day is considered a new menstruation if the menstrual bleeding has completely stopped and signs of purity have been observed, and there was a period of purity between the two bleeding incidents. However, if the menstrual bleeding has not completely stopped, then the discharge (Kudra) is considered an extension of the menstruation. "We did not consider the brownish (kudra) and yellowish (sufra) discharge after purity to be anything." The understanding of this is that it is considered menstruation if it occurs during the time of menstruation. Therefore, the brownish (kudra) and yellowish (sufra) discharge during the time of menstruation is considered menstruation, prohibiting what menstruation prohibits.