Whenever the Prophet ﷺ went to the lavatory, he used to say: "Allahumma inni aʿudhu bika min al-khubuthi wal khaba'ith."  

كَانَ النَّبِيُّ ﷺ إِذَا دَخَلَ الْخَلاَءَ قَالَ اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْخُبُثِ وَالْخَبَائِثِ