Abstract
The microbiological reduction of the 5‐ene bond of cholesterol (cholest‐5‐en‐3β‐ol) to form coprostanol (5β‐cholestan‐3β‐ol) occurs in the gastrointestinal tract of many species. Data are presented which show that this activity occurs predominantly in the ceca in cholesterol fed rats. This explains the report by others that the removal of the ceca causes coprostanol to disappear from the feces.