Sure, changing the color of your product up is sure to garner some attention. But you know what else will get people talking? When that new hue causes something else to change color: Burger King customers are airing their bathroom business on the Internet, claiming that the chain’s black Whopper bun for Halloween is turning their poop green.

The bun’s coloring comes from A.1. Thick and Hearty Sauce, Burger King says, and contains less than 1% food dye. And the nutrition facts for the limited-edition burger say that flavorings and food colorings in the bun “are commonly used in the industry and within the safe and Acceptable Daily Intake (ADI) approved by the Food and Drug Administration (FDA),” points out the Huffington Post.

While it’s unclear which colors are used specifically, Medical Daily reports that green dyes are often used in black food coloring.

No matter the catalyst, there’s now a #GreenPoop hashtag on social media, devoted to the colorful potty talk. It’s not something you want to browse if you’re eating lunch, or if you don’t like seeing photos of other people’s feces, because that is definitely something that’s happening.

Reports started to pop up last week when the burger debuted:

Of course, now much of the Twitter chatter is people pledging to try the burger just to see if it really does turn their poop green, which I guess is a win for Burger King?

Is this really a widespread thing, or is it just a widely spread story? It’s unclear, but we did hear from at least one Consumerist reader who swears this is a very real phenomenon.

“The story about the black Whooper coming out green is true, I 100% guarantee this,” writes Chris. “Not just greenish – a dark St. Patrick’s Day green.”

I’d like to take a moment to personally thank you, reader Chris, for not including photographic evidence.

We’ve also reached out to Burger King to see if the company has any comment on the claims of odd poo hues, and will update this post if we hear back.

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