Dua for Entering the Bathroom (Toilet)
اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْخُبُثِ وَالْخَبَائِثِ
Transliteration: Allahumma inni a'udhu bika minal-khubuthi wal-khaba'ith.
Translation: O Allah, I seek refuge in You from the male and female devils (or: from all evil and evil beings).
Source: Sahih al-Bukhari 142; Sahih Muslim 375
When to recite: Before entering the toilet, stepping in with the left foot. Say it before going in, not inside. The left is for the opposite of honourable things (Sunan Abi Dawud 33), and scholars apply this to the feet.