When it comes to finding synonyms for the phrase "spit up on," there are several options to choose from. Some alternative phrases that can be used include "vomit on," "upchuck on," "retch on," "hurl on," "puke on," or "regurgitate on." All these phrases are commonly used to describe the action of expelling food or liquid from the mouth or stomach in an unpleasant manner. While the medical term for this is "reflux," using more colloquial terms is often more relatable and easily understood by the general public. Regardless of which phrase is used, they all describe the same thing - an uncomfortable and sometimes embarrassing bodily function!