What is the expiation for one who has anally penetrated his wife more than once during her menstrual period, and what is the ruling on one who has sexually penetrated his wife during her menstrual period out of ignorance on the part of both of them?

There is no sin or expiation for someone who has intercourse with his wife, or recites the Qur’an, or prays while unaware that she is menstruating, because he did not do so intentionally. As for anal intercourse with one's wife, it is forbidden and a major sin, for which there is no expiation. The one who commits it must repent, feel remorse, and resolve not to do it again.