Narrated Anas: Whenever the Prophet went to answer the call of nature, he used to say, "Allah-umma inni a`udhu bika minal khubuthi wal khaba'ith i.e. O Allah, I seek Refuge with You from all offensive and wicked things (evil deeds and evil spirits).
Hadith ReferenceSahih Bukhari / The Book of Wudu (Ablution) / Hadith: 142
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة