Abu Dawud Book 1, Hadith Number 8.

Chapter : Disapproval of facing the qibla while releiving oneself.

Narated By Abu Hurairah : The Apostle of Allah (PBUH) said: “I am like a father to you. When any of you goes to the privy, he should not face or turn his back towards the qiblah. He should not cleanse with his right hand.