Are a woman's prayer and fasting valid, according to the Maliki school of thought, if bloody discharges of varying characteristics continue for a long time, with overlapping periods of menstruation and brown discharges, and an inability to ascertain the time of purity with certainty?

We issue a fatwa that yellow and brownish discharges (ṣufrah and kudrah) are not considered menstruation outside of the regular period, unless they are connected to menstrual blood. Recurrent bleeding is considered menstruation if there are fifteen days between it and the cessation of the previous bleeding, which is the minimum period of purity between two menstruations according to the majority of scholars. So, if you see blood after fifteen days from the cessation of the previous bleeding, it is menstruation, unless its duration exceeds fifteen days; otherwise, it is irregular bleeding (istiḥāḍah).