It's not unheard of to nounify a verb so you might be able to use:

Puke: He was found lifeless, lying in a pool of his own puke.

Upchuck: The volume of upchuck was astounding...who could possibly have so much food and liquid in their stomach at one time?

And kinda related...bile. The liquid, non-food specific stomach acid that is sometimes ejected after a person has no more food in their stomach but the spasms continue to push out the contents of the stomach.

Per MW-Online's definition of vomit:

Synonyms

barf, gag, heave, hurl, vomit, retch, spew, spit up, throw up, upchuck...of these, the following can be used in a nounified version: barf, spit up, throw up, (and as mentioned above, upchuck)


Vomitus

Matter from the stomach that has come up into and may be ejected beyond the mouth, due to the act of vomiting.