What is the ruling on prayer and ritual purity upon seeing rigid brown spots resembling dirt, outside of the menstrual period or during it, and is it obligatory to repeat the prayers of the past month that were performed while ignoring them?

If a woman sees a brown spot after her menstruation has ended and she has purified herself, it is not considered menstruation. Rather, it is a discharge (kudrah) that is not counted as menstrual blood unless it occurs during her usual period or is connected to bleeding. It is not necessary to disregard it if it appears after the cessation of menstruation. However, whatever comes during menstruation is considered menstruation.