feces vs excretion

feces and excretion both are nouns.

Word	Noun	Adjective	Verb	Adverb
feces	Yes	No	No	No
excretion	Yes	No	No	No

As nouns, excretion is a hypernym of feces; that is, excretion is a word with a broader meaning than feces:

feces: solid excretory product evacuated from the bowels
excretion: waste matter (as urine or sweat but especially feces) discharged from the body

Other hypernyms of feces include body waste, excrement, excreta, excretory product.

feces (noun)	excretion (noun)
solid excretory product evacuated from the bowels	the bodily process of discharging waste matter
	waste matter (as urine or sweat but especially feces) discharged from the body