Stercobilin

Brown pigment of bile origin

Stercobilin is a tetrapyrrolic bile pigment and is one end-product of heme catabolism. It is the chemical responsible for the brown color of human feces and was originally isolated from feces in 1932. Stercobilin can be used as a marker for biochemical identification of fecal pollution levels in rivers.

This keyword could refer to multiple things. Here are some suggestions: