excreta vs vomitus

excreta and vomitus both are nouns.

Word	Noun	Adjective	Verb	Adverb
excreta	Yes	No	No	No
vomitus	Yes	No	No	No

As nouns, vomitus is a hyponym of excreta; that is, vomitus is a word with a more specific, narrower meaning than excreta:

excreta: waste matter (as urine or sweat but especially feces) discharged from the body
vomitus: the matter ejected in vomiting

excreta (noun)	vomitus (noun)
waste matter (as urine or sweat but especially feces) discharged from the body	the matter ejected in vomiting