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