Purity: Requirements After Excessive and Medium Istiḥāḍah Stops
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 410:
When the bleeding of a woman with excessive istiḥāḍah completely stops, if she knows that from the time she became engaged in performing ghusl for the previous prayer there has not been any discharge of blood, it is not necessary for her to perform ghusl again. Apart from this case, she must perform ghusl based on obligatory precaution. As for a woman who has medium istiḥāḍah, it is not necessary for her to perform ghusl if her istiḥāḍah has completely stopped.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)