Is it permissible to have anal sex with one's wife if the wife does not object to it?

Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

We have already replied that having anal sex with one's wife is forbidden in Sharia. Her consent to do so does not make it Halal.
For more details, please read the Fatwa: 81358.
Allah knows best.