Istihaadah is defined as: a flow of ill-fated blood* from the lowest point in a woman’s womb in times other than the times of menstruation and postpartum, and its exit is before the completion of the age of nine years, or after that, and it is not called istihaadah unless the bleeding continues after the longest period of menstruation or postpartum in the event that the blood is connected time of one.
There are many opinions of the jurists regarding the longest period of menstruation and childbirth, and the following is a statement of this issue:
The Maliki, Shafi'i, and Hanbali schools say that the most menstrual period is fifteen days, while the Hanafis say that the most is ten days.
The Hanafis and Hanbalis said that the maximum period of postpartum bleeding is forty days, while the Malikis and Shafi’is said that the maximum period is sixty days.
The continuation of bleeding after the end of the most menstruation or postpartum period is considered istihaadah, neither menstruation nor postpartum, and the woman istihadha is not like a menstruating woman or childbirth; She prays, fasts, and has intercourse even with bleeding.