After recently unveiling a new Whopper, Burger King has received complaints that the item causes green poop.
The Halloween Whopper features a dark bun served with its signature sandwich. While the company hasn’t specified what colors of food dye are used in the buns, Medical Daily noted that green dyes are often used in black food coloring, according to The Huffington Post.
The New York Daily News reports that certain green dyes turn poop green, but that green stool can also be a sign of bile not breaking food down properly.
Burger King told ABC News that the black bun contains less than 1 percent of food dye. According to the company, the ingredients 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)."
Since the burger was released, the hashtag #GreenPoop has become popular on Twitter.
Twitter user Marie Horselamp wrote: “don’t rly care how it tastes, I just want that halloween burger from @burgerking for the rad green poop.”
Another Twitter user suggested that Burger King bring the black Whopper back for St. Patrick’s Day.