This hadith has been narrated on the authority of Isma'il b. Khalid with the same chain of transmitters and the words are:
" One amongst us would relieve himself as the goats do without anything mixing with its excrement."
Reference: Sahih Muslim 2966 b
In-book reference: Book 55, Hadith 18
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7074