1. The minimum duration of menstruation is 1 day, and the maximum duration of it is 15 days. If blood flows for more than 15 days, the blood flowing after the 15th day is considered istihada (non-menstrual blood; bleeding other than menstrual and postnatal bleeding).
2. The minimum duration of purity between two periods is 13 days. If a woman starts to bleed again before a minimum of 13 days have passed, that blood will not be considered menstrual, but istihada.
3. The blood that is discharged from the vagina of a girl who is under the age of 9 and from a woman on menopause [who is over the age of 50] is not considered menstrual, but istihada.
4. The blood discharged from a pregnant woman is considered istihada, not menstrual.
5. Having sexual intercourse with a woman who is experiencing istihada (non-menstrual bleeding) is haram. But this act is permissible in the other three madhhabs. If a woman experiencing postnatal bleeding becomes pure from it before 40 days are over, it will not be permissible to have sexual intercourse with her until she completes 40 days. However, this is permissible in the other three madhhabs. According to the three madhhabs, when a woman stops menstruating, it is not permissible for her to engage in sexual intercourse without taking a ghusl. But it is permissible according to the Hanafi Madhhab. When a woman is menstruating or experiencing postnatal bleeding, it is permissible for her husband to touch what is between her navel and knees except her genital area according to the Hanbali Madhhab. But it is not permissible according to the Shafi’i and Maliki Madhhabs. As for the Hanafi Madhhab, it is not permissible according to Imam-i A’zam but permissible according to Imam-i Muhammad. And the fatwa is what Imam-i Muhammad said.
6. The maximum duration of nifas (postnatal bleeding) is 40 days, as in the Hanafi Madhhab. There is not a minimum duration for it.
7. When a woman is experiencing postnatal bleeding, she is considered pure on the days when blood has not flowed, so she takes a ghusl then and can perform any act of worship. However, she has to refrain from performing salat and fasting during the days when she sees bleeding. She should go by this rule until she completes 40 days.