If menstruation continues for more than 15 days is still salah invalid?
بسم الله الرحمن الرحيم
(Fatwa: 317/299/L=3/1439)
In case the menstruation cycle of a woman prolongs more than fifteen days then the detail is that if the woman has a habit then the days of her habit shall be counted as the days of menstruation and the remaining days shall be counted as istihazah and illness. And in case the woman has no habit then ten days shall be counted as menstruation and rest will be considered istihazah. The salah during the period of menses is exempted. However, during istihazah, salah is not exempted rather it is mandatory to offer salah in the same state. Thus the salah which the woman missed during the istihazah days she will have to offer it.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband