feces vs fecal matter

feces and fecal matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
feces	Yes	No	No	No
fecal matter	Yes	No	No	No

As nouns, feces and fecal matter are synonyms defined as:

feces and fecal matter: solid excretory product evacuated from the bowels

Other synonyms of feces include BM, dejection, faecal matter, faeces, ordure, stool.

feces (noun)	fecal matter (noun)
solid excretory product evacuated from the bowels	solid excretory product evacuated from the bowels