Other than the green stool, you have no other discomforts? If so, it is mostly caused by something you ate.
The most common reason for green stool is a dietary habit or change. Food that can cause green stools include:
Dark green vegetables and green powder supplements contain a lot of chlorophyll, the chemical that allows plants to make energy from the sun. This can turn your Cleveland Brown into a Green Bay Packer. That doesn’t mean there’s something wrong. Keep eating those greens!
Some foods contain food coloring that doesn’t get processed properly. This can also leave a colorful residue in your stool. So if you wake up after a St. Patrick’s Day spent imbibing green beer and notice something off when you go to the bathroom, you probably just need some water.
The food coloring you consume doesn’t necessarily have to be green in order to make your poop green. Purple, blue, and black dyes may also lead to green poop. For example, in 2015, fast food chain Burger King went viral with posts from individuals who had purchased their “Halloween Whopper,” which had a black bun. Many people who partook in the Halloween Whopper reported that it turned their poop green after eating it.