How is bleeding classified when it recurs after the normal menstrual period has concluded?
Chapter on Menstruation
Al-Mughni
Book of Purification
Primary text
If the bleeding recurs after the established habit period, it is either impossible for it to be menstruation or it is possible. If it is impossible to be menstruation because it exceeds the maximum duration of menstruation and there is not the minimum period of purity between the two flows, then the entire duration is considered istihada, whether it repeats or not. If it is possible for it to be menstruation, this occurs in two scenarios: either when combining it with the previous flow does not result in a period exceeding fifteen days between the two ends, or when the purity between the two flows is at least the minimum period of purity (thirteen or fifteen days), and each flow is capable of being menstruation individually (one day and night or more). If it repeats under the second condition, the two flows are considered two menstruations. If the purity between them is eleven days or less, they are one menstruation, provided the time between the starts of the flows does not exceed fifteen days and the minimum purity interval is not breached by the intervening period.
Supporting text
If the intervening purity is twelve days, it cannot be entirely a single menstruation due to exceeding the maximum duration, nor two menstruations because the minimum purity interval is not met. In this case, the portion aligning with the established habit is menstruation, and the other is istihada. The woman must make up obligatory fasts if she failed to perform them during a time later determined to be menstruation. Conversely, if she performed worship during a time later determined to be purity, she must make up the obligatory acts she neglected.