What is the ruling on one spouse inserting a finger into the other's anus while wearing medical gloves, and what is the ruling on anal intercourse with one's wife while using a condom?

There is no difference in the ruling on anal sex with a woman, whether directly or through a barrier. It is one of the major sins that expose the perpetrator to the curse and wrath of Allah. The prohibition is not limited to the reason of impurity only. Furthermore, inserting a finger into the anus is more forbidden than anal penetration with the organ, and a woman doing this to a man is more abhorrent because it is a perversion of nature and a gateway to sodomy, which is the gravest indecency. Al-Qurtubi mentioned, citing Tawus, that the beginning of the actions of the people of Lot was engaging in anal sex with women. The medical, moral, and psychological harms resulting from this have been previously explained.