Purity: Permissibility of Mosque Entry, Recitation, and Intimacy
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 426:
It is lawful for a mustaḥāḍah who has performed her obligatory ghusls to go to a mosque and stay in it, and to recite a verse with an obligatory sajdah,[1] and for her husband to have sexual intercourse with her, even if she has not done the other things that she would have done for prayers, such as changing the piece of cotton [or sanitary pad/another absorbent item]. In fact, these acts are permitted even if she has not performed ghusl.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)
1
These verses are mentioned in the fifth part of the list mentioned in Ruling 354.