Rule: If a woman who has a certain length of time for her menstruation sees bleeding for more than 10 days, she is considered to have istihada (non-menstrual bleeding). That is, it means that there are days that are not considered menstrual though there is bleeding. When a woman bleeds for more than 10 days, she must refer to her previous menstrual period to see whether her current days of bleeding coincide with her previous menstrual period. If 3 or more days of bleeding coincide with her previous menstrual period, only the days that coincide with her previous menstrual period are considered menstrual bleeding, and all the remaining days of bleeding are considered istihada. She must make up the salats that she missed during the days of istihada later on. If 2 days or less than 2 days coincides with her previous menstrual period, they are not taken into account.

Examples:

1. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 17 days and then sees bleeding for 11 days, there is istihada as bleeding has exceeded 10 days. Because 3 days of bleeding [the 9th, 10th, and 11th days] coincide with her previous menstrual period, these 3 days are considered menstrual bleeding, and the first 8 days are considered istihada. Her purity period does not change, but her menstrual period has decreased to 3 days. She must make up the salats that she missed during the days of istihada later on.

2. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 17 days and then sees bleeding for 12 days, there is istihada as bleeding has exceeded 10 days. Because 4 days of bleeding [the 9th, 10th, 11th, and 12th days] coincide with her previous menstrual period, these 4 days are considered menstrual bleeding, and the first 8 days are considered istihada. Her purity period does not change, but her menstrual period has decreased to 4 days. She must make up the salats that she missed during the days of istihada later on.

3. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 16 days and then sees bleeding for 14 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 10th, 11th, 12th, 13th, 14th days] coincide with her previous menstrual period, these 5 days are considered menstrual bleeding, and the first 9 days are considered istihada. Neither the number of her purity period nor the number of her menstrual period changes. She must make up the salats that she missed during the days of istihada later on.

4. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 27 days and then sees bleeding for 11 days, there is istihada as bleeding has exceeded 10 days. Because 3 days of bleeding [the 1st, 2nd, and 3rd days] coincide with her previous menstrual period, these 3 days are considered menstrual bleeding, and the remaining 8 days of bleeding are considered istihada. Her purity period has increased to 27 days, and her menstrual period has decreased to 3 days. She must make up the salats that she missed during the days of istihada later on.

5. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 26 days and then sees blood for 15 days, there is istihada as bleeding has exceeded 10 days. Because 4 days of bleeding coincide with her previous menstrual period, these 4 days of bleeding [the 1st, 2nd, 3rd, and 4th days] are considered menstrual, and the remaining 11 days of bleeding are considered istihada. Her purity period has increased to 26 days. Her menstrual period has decreased to 4 days. She must make up the salats that she missed during the days of istihada later on.

6. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 25 days and then sees blood for 11 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 1st, 2nd, 3rd, 4th, 5th days] coincide with her previous menstrual period, these 5 days are considered menstrual bleeding, and the remaining 6 days are considered istihada. Her purity and menstrual periods do not change. She must make up the salats that she missed during the days of istihada later on.

7. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 24 days and then sees blood for 12 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 2nd, 3rd, 4th, 5th, and 6th days] coincide with her previous menstrual period, these 5 days are considered menstrual. Day 1 and the remaining 6 days [the last 6 days], that is, 7 days of bleeding in total, are considered istihada. The number of her purity and menstrual days does not change. She must make up the salats that she missed during the days of istihada later on.

8. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 22 days and then bleeds for 14 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 4th, 5th, 6th, 7th, 8th days] coincide with her previous menstrual period, these 5 days are considered menstrual bleeding. The first 3 days and the last 6 days of bleeding, that is, 9 days of bleeding in total, are considered istihada. The number of her purity and menstrual days does not change. She must make up the salats that she missed during the days of istihada later on.

9. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 16 days and then bleeds for 16 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 10th, 11th, 12th, 13th, 14th days] coincide with her previous menstrual period, these 5 days are considered menstrual bleeding. The first 9 days and the last 2 days of bleeding, that is, 11 days of bleeding in total, are considered istihada. Her purity and menstrual periods do not change. She must make up the salats that she missed during the days of istihada later on.

10. A woman’s habit is 25 days of purity and 5 days of menstruation. If she remains free from menstruation for 20 days and then bleeds for 15 days, there is istihada as bleeding has exceeded 10 days. Because 5 days of bleeding [the 6th, 7th, 8th, 9th, 10th days] coincide with her previous menstrual period, these 5 days are considered menstrual bleeding. The first 5 days and the last 5 days of bleeding, that is, 10 days of bleeding in total, are considered istihada. Her purity and menstrual periods do not change. She must make up the salats that she missed during the days of istihada later on.