Purity: Transition to Excessive Istiḥāḍah After Morning Prayer
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 398:
If the slight or medium istiḥāḍah of a woman becomes excessive after ṣubḥ prayers and she remains in this state, she must observe the laws mentioned in Ruling 394 regarding ẓuhr, ʿaṣr, maghrib, and ʿishāʾ prayers.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)