Is it permissible to continue fasting and praying, or must one stop both, with the discharge of blood after the insertion of an IUD, and the inability to distinguish menstrual blood from other types?

The maximum duration of postpartum bleeding (nifas (definition)) is forty days. Any bleeding beyond this period is considered istihadah (definition) (non-menstrual vaginal bleeding), unless it coincides with the woman's regular menstrual cycle. There is also an opinion that it can extend to sixty days.

If the days of bleeding do not exceed fifteen days, then all of it is considered menstruation (hayd), during which fasting and prayer are impermissible. One must wait for purity, then perform ghusl (definition) (ritual purification bath) and pray.

If the duration of bleeding exceeds fifteen days, it is considered istihadah.