For people who have never had dark green stool before, seeing it for the first time can be disconcerting. So what does green poop mean? Well, typically, a green stool means that your body is doing its job correctly. But, that said, if your poop is dark green and something doesn’t seem “right,” be sure to consult your physician to get checked out.
Poop should be light-to-medium brown in color, but even light green stool is on the spectrum of “normal” poop. There are a lot of other reasons and factors that influence the color of your stool … but first …
Setting the Baseline: What is Poop, exactly?
Once food and drink enter your stomach, bile and the rest of your digestive system gets to work, breaking down your food and extracting essential nutrients. Then, your digestive system moves what is left into your large and small intestines. Once there, the small intestine’s walls go to work, absorbing water, and the rest of the digested nutrients, into the bloodstream. The next stop is your large intestine, where the remaining undigested food is changed into a stool. Finally, the stool moves into the bowel, where it stays until you have a bowel movement.2
That’s how poop is made … but what is poop made of?
Simply put, poop is a combination of bile – that yellow-green fluid produced by your liver to digest fats – and what you eat.
Strictly speaking, poop is composed of inorganic material, like calcium phosphate and iron phosphate, as well as organic material, such as cellulose, protein, bile and fats, and water.3
Your stool also contains dead bacteria and cholesterol. Its characteristic brown color occurs during digestion. Bilirubin is an orange-yellow substance formed in the liver which contains old red blood cells. When the bilirubin mixes with bile and other substances in your waste, the resulting color is usually a shade of brown.
And the smell? Well, you can thank a host of chemicals produced by bacteria (including hydrogen sulfide) for the odor.4
You Are What You Eat …
Green stool doesn’t just happen because of specific actions of your digestive system, or from the work of your intestines. What you give your body as fuel and sustenance has a direct impact on the waste you produce when you go to the bathroom. So, if you’re finding that you’re regularly producing green or dark green stool, what you’re eating, and how much of it, may be influencing the color of your stool.
Green foods (surprise!) can make your stool appear greener in color. Green leafy vegetables are high in chlorophyll. And chlorophyll is central to the photosynthesis process in plants, but it is also responsible for the green coloration in leaves.5
It stands to reason, then, that the more green leafy vegetables you consume, the more likely it is that your poop will be green. Chlorophyll-heavy plants include kale, spinach, arugula, and Swiss chard, to name a few. And while leafy greens that are heavy in chlorophyll are linked to blocking potentially dangerous ailments, they may cause your stool to be a darker green color.6
So, if you’re on a leaf-heavy diet, chances are that you don’t need to worry about what your dark green poop means.
Food dyes are prevalent in many everyday foods and drinks, and they may also be responsible for your greenish stool. Some are obvious, but some may be less obvious. It probably comes as no surprise that sodas, sugary drinks, and candy are chock-full of dyes. But other foods, like farmed salmon, have dyes added to make them look more “natural” or appetizing. Even pickles and yogurt may have dyes added to them.
Many of the dyes used in American food and drink are manufactured, as opposed to extracts from plants, fruits, or vegetables. They aren’t readily absorbed by your body. When you eat foods containing these dyes, they move through your digestive system without being absorbed, and they wind up in your stool, possibly turning it green.7
Coffee and Alcohol
It isn’t just soda and sugary drinks with dye that can impact the color of your stool. Drinks like alcohol and coffee can also affect how your body is digesting your food and how it is processed.8,9
Coffee and alcohol are laxatives.They speed up your digestion, meaning the digestive process isn’t always complete. When this happens, your stool doesn’t have time to change from its small intestine green color to its more “normal” brown.10 The result is that your stool may not only be loose, but it may be green, too.
If you’ve recently changed your diet, or if you’re on a specific type of diet, you increase your chances that your poop will be greener than you’re used to.
Similar to the leafy greens, if you’ve recently become vegetarian, you may notice that your poop is greener due to the increased consumption of plants high in chlorophyll. Additionally, high-fat diets such as keto produce more bile to break down the fatty foods, which may stay in your stool when it is time to go.11
As you can see, a lot of variables can cause your body to produce green stool. By paying attention to what you’re eating – and how much, in some cases – you’ll have a better idea of whether or not the green color in your poop is perfectly normal, or something you may want to consult with your doctor about.
For more on healthy digestion and bodily functions, keep reading here:
What is Your Poop Trying to Tell You?
What Causes Bright Yellow Urine? (4 possible reasons)
How to Get Rid of Bloating Fast (3 natural remedies to try)
3. “Feces.” Encyclopaedia Britannica: Macropedia. 15th ed. Chicago: Encyclopaedia Britannica, Inc, 1987. 710. Print