"I've had another case that was really interesting," Milov adds, "and that was somebody who swallowed sunflower seeds—[and] also, the shells." Upon examining the patient's lower digestive tract, Milov found "all these very prickly seeds that were congealed around gum," forming a body that he describes as "like a porcupine."
Whereas the real (if remote) prospect of an internal quilling ought to be enough to discourage anyone from regularly swallowing gum, the mythical seven-year deterrent persists. Because it causes no real harm, and in fact probably serves to prevent many cases like those Milov describes, the urban legend seems likely to stick around for the foreseeable future. Unlike, thankfully, that wad of spearmint gum you swallowed in high school.