Reference: al-Muntaqaa min Fataawa Shaykh Saalih al-Fowzaan – Volume 1, Page 439, Fatwa No.262
Question: When I need to go to the toilet [to answer the call of nature] – may Allaah honour you [O Shaykh] – I take with me a book or newspaper [to read] whilst I am in there. So is this permissible?
Response: It is not permissible to take anything into the toilet which has the mention of Allaah (‘Azza wa Jall) in it, be it a book, newspaper or other than that, for that which it entails in exposing the mention of Allaah (‘Azza wa Jall) therein.