The latest cream flavor to come out of something called "the Oreo Wonder Vault" has consumers wondering why their poop suddenly looks like it could've come from a unicorn. Two weeks ago, Oreo released a limited edition of its cookie with a vanilla shell and a filling flavored like the love-it-or-hate-it marshmallow candy Peeps. One reviewer claims the filling is the same one used in the Marshmallow Crispy Oreos, but with one major difference: It's bright pink and appears to turn your mouth—and even your dung—bright pink, too. "My spit looks like Pepto-Bismol" hours after eating the cookies, one Twitter user complains, per Delish. Adds another, "My roommate ate a whole pack of Oreo Peeps and left a pink stain in the toilet."
Indeed, some who ate a lot of cookies say the dye turned their feces various shades of pink, from "bright pink" to "reddish-pink," reports BuzzFeed; BuzzFeed employees who ate only one cookie say their bowel movements were no more colorful than usual. While Oreo has yet to comment, USA Today previously reported that stuffing your face with foods heavy in dyes can produce "a greater spectrum in your rectal rainbow." In 2015, for example, people who ate a Halloween-themed Burger King Whopper with a black bun complained its concentrated dye made their excrement "as green as the Irish countryside." A doctor at the time suggested it was nothing to worry about. Reddish stool should be checked by a doctor, though, as it could be a sign of internal bleeding. (Here are 5 ways to poop better.)