excretion vs body waste

excretion and body waste both are nouns.

Word	Noun	Adjective	Verb	Adverb
excretion	Yes	No	No	No
body waste	Yes	No	No	No

As nouns, excretion and body waste are synonyms defined as:

excretion and body waste: waste matter (as urine or sweat but especially feces) discharged from the body

Other synonyms of excretion include excrement, excreta, excretory product.

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