What is the ruling for one who has anal intercourse with his wife during the daytime in Ramadan?

Find answers

Whoever does that at any time – in Ramadan or otherwise – has committed a major, cursed, and forbidden transgression.

Doing that during the day in Ramadan invalidates one’s fast, the fast must be made up, and expiation must be offered as in the case of intercourse. This is by consensus of the four schools of thought.