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." (ES)
Reference (ES): Sahih Muslim 2966 b (ES)
In-book reference (ES): Book 55, Hadith 18 (ES)
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7074 (ES)