Whenever Messenger of Allah ﷺ went to answer the call of nature, I along with another boy used to accompany him with a tumbler full of water. (Hisham commented, "So that he might wash his private parts with it.)"  

سَمِعْتُ أَنَسَ بْنَ مَالِكٍ يَقُولُ كَانَ النَّبِيُّ ﷺ إِذَا خَرَجَ لِحَاجَتِهِ أَجِيءُ أَنَا وَغُلاَمٌ مَعَنَا إِدَاوَةٌ مِنْ مَاءٍ يَعْنِي يَسْتَنْجِي بِهِ  

Whenever Messenger of Allah ﷺ went to answer the call of nature, I along with another boy from us used to go behind him with a tumbler full of water.  

سَمِعْتُ أَنَسًا يَقُولُ كَانَ رَسُولُ اللَّهِ ﷺ إِذَا خَرَجَ لِحَاجَتِهِ تَبِعْتُهُ أَنَا وَغُلاَمٌ مِنَّا مَعَنَا إِدَاوَةٌ مِنْ مَاءٍ  

"When the Messenger of Allah ﷺ would go to the toilet, I and another boy like me would bring a small leather vessel of water and he would clean himself with water."  

سَمِعْتُ أَنَسَ بْنَ مَالِكٍ يَقُولُ كَانَ رَسُولُ اللَّهِ ﷺ إِذَا دَخَلَ الْخَلاَءَ أَحْمِلُ أَنَا وَغُلاَمٌ مَعِي نَحْوِي إِدَاوَةً مِنْ مَاءٍ فَيَسْتَنْجِي بِالْمَاءِ  

[Machine] I heard Anas saying that when the Messenger of Allah ﷺ wanted to relieve himself, he would ask me and another boy to bring him a container of water.  

سَمِعْتُ أَنَسًا يَقُولُ كَانَ رَسُولُ اللهِ ﷺ إِذَا خَرَجَ لِحَاجَتِهِ نَجِيءُ أَنَا وَغُلَامٌ مِنَّا بِإِدَاوَةٍ مِنْ مَاءٍ  

When the Messenger of Allah ﷺ entered the privy, a servant and I used to carry a skin of water, and a pointed staff, and he would cleanse himself with water. (Using translation from Muslim 271a)  

أَنَّهُ سَمِعَ أَنَسَ بْنَ مَالِكٍ يَقُولُ كَانَ رَسُولُ اللهِ ﷺ يَدْخُلُالْخَلَاءَ فَأَحْمِلُ أَنَا وَغُلَامٌ نَحْوِي إِدَاوَةً مِنْ مَاءٍ وَعَنَزَةً فَيَسْتَنْجِي بِالْمَاءِ  

[Machine] I heard Anas saying, "The Messenger of Allah ﷺ used to take me with him when he went out for his personal needs, and one of us would bring a container of water."  

قَالَسَمِعْتُ أَنَسًا يَقُولُ كَانَ رَسُولُ اللهِ ﷺ إِذَا خَرَجَ لِحَاجَتِهِ نَجِيءُ أَنَا وَغُلَامٌ مِنَّا بِإِدَاوَةٍ مِنْ مَاءٍ  

[Machine] I heard Anas saying that the Messenger of Allah ﷺ used to go to the bathroom and I would follow him along with a young boy from the Ansar, carrying a container of water, so he would clean himself with it after defecating. This narration is found in Sahihayn (i.e. Sahih Bukhari and Sahih Muslim) from the hadith of Shu'bah ibn al-Hajjaj.  

سَمِعْتُ أَنَسًا يَقُولُ كَانَ رَسُولُ اللهِ ﷺ يأْتِي الْخَلَاءَ فَأَتَّبِعُهُ أَنَا وَغُلَامٌ مِنَ الْأَنْصَارِ بِإِدَاوَةٍ مِنْ مَاءٍ فَيَسْتَنْجِي بِهَا مُخَرَّجٌ فِي الصَّحِيحَيْنِ مِنْ حَدِيثِ شُعْبَةَ بْنِ الْحَجَّاجِ