Reasons your poop isn’t brown

Generally, healthy poop is a shade of brown. If your poop is a different color, like green, you might feel concerned.

There are plenty of possible causes, so you may not need to worry. Certain foods, supplements, medications, and health conditions can cause poop to change color.

In this article, we’ll explore what might be causing your poop to be green or another less common color.

We’ll also look at what your poop's consistency can tell you.

With the ZOE at-home test, you can learn about your unique gut microbiome. We'll provide a breakdown of the “good” and “bad” bugs living in your gut and send you personalized nutrition advice so you can support the “good” ones. 

Take our free quiz to get started.

What you eat

Certain foods can cause your poop to turn green. 

Chlorophyll is a compound that gives a green color to plants. So, if you eat lots of chlorophyll-rich foods, your poop can turn green. 

Some foods that may cause green poop include:

  • leafy greens, like spinach, kale, and watercress

  • asparagus

  • algae, such as spirulina

  • wheatgrass

  • blueberries

  • pistachios

Also, foods with green dye can have the same effect.

If food is the cause of your green poop, you probably don’t need to worry. In fact, the foods listed above can be a good addition to a balanced diet. 


If you have a bacterial infection, your doctor might prescribe antibiotics to kill the harmful bacteria. 

However, certain bacteria in your gut are responsible for the brown color of your poop. If they’re killed by antibiotics, your poop may turn a different color, likely green or yellowish. 

This is more likely if the antibiotics you’re taking are particularly strong.


Iron supplements can cause green (and even black) poop. This is a normal side effect, so you don’t need to be concerned.

Also, some companies sell supplements containing chlorophyll. They can have the same effect as chlorophyll-rich plants, giving your poop a greenish color.

Health conditions

Poop gets its brown color from spending time in your gut. 

If it moves through your system too quickly — if you have diarrhea, for example — your poop may turn green.

Some health conditions that affect your gut can also cause green poop. They’re usually ones that impact the body’s ability to digest effectively. 

Bile is a substance in the stomach that helps break down food. When your body is having difficulty digesting, food and bile may pass through the gut too quickly, resulting in green poop.

Some of these conditions include:

Bacteria and pathogens

Certain bacteria can give poop a green shade if the bacterial infection causes food to move through your system too quickly. These bacteria include Salmonella, for example, which can cause severe food poisoning. 

The parasite Giardia lamblia may also cause green poop. It can enter your system through contaminated food and water. It can also pass from person to person or from dogs to people.

Other poop colors

Your poop may be a different color from brown or green for many reasons.

Hemorrhoids, bleeding in the lower digestive tract, and red foods, like beets, can cause red poop.

If you have yellow poop, excess fat or an infection of the small intestine might be the cause.

White poop may stem from a lack of bile, but it can also happen if you take certain antidiarrheal medications.

If you have black poop, it might be because you’re taking iron supplements. But black poop can also result from bleeding of the upper digestive tract.

If you’re concerned that you might have bleeding in your gut, speak with a healthcare professional.

What does your poop tell you?

Your poop can give you important insights into what’s going on in your body. 

Color changes may just result from something you ate, but they can also point to certain health conditions. 

The consistency of your poop can also give you clues about your digestive health. Healthcare professionals often use the Bristol Stool Scale to assess the different textures.

It’s a scale from 1–7, with the ideal texture being around 3 or 4. This means that your poop is somewhere between soft and firm, and it sinks in the toilet.

Hard poop (types 1 or 2) can be a sign that you aren’t eating enough fiber or drinking enough water.

Soft poop (types 5–7) indicates diarrhea. This means that you may have an infection, a food intolerance, or some other digestion problem.

If your poop floats, there could be lots of fat in it. This can happen if your body isn’t absorbing all the fat and nutrients in your food.

Overall, everyone has different bowel habits and different poop. It’s a good idea to stay on top of any changes, especially if they happen at the same time as other symptoms. 

If you’re concerned about any poop-related changes, let a healthcare professional know.

At ZOE, we recently teamed up with world-leading scientists to create the Blue Poop Challenge.

Thousands of people ate ZOE’s blue muffins so our scientists could research how long food spends traveling through the gut. We found that a lower transit time may indicate better gut health. 


Certain foods, medications, and supplements can cause your poop to turn green. 

Some bacteria, such as Salmonella, may also cause green poop. 

Beyond bacterial infections, some health conditions, like IBS or celiac disease, can also cause food and bile to pass through your digestive system too quickly. This can also result in poop that’s greener than usual.

Your poop may also turn other colors, such as red, yellow, white, or black. Just like with green poop, there can be various reasons, and not all are a cause for concern.

You can also learn about your digestive health by paying attention to your poop’s consistency.

If you think your poop color might be related to a health condition, speak with a healthcare professional.

At ZOE, we know that everyone’s gut health and bowel habits are unique. 

With the ZOE at-home test, you can learn about your body’s blood sugar and blood fat responses, as well as which “good” and “bad” bugs are living in your gut. Then, we’ll provide you with personalized nutrition advice.

Take our free quiz to get started.


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The case of lime-green stool: A case report and review of occult blood testing in the emergency department. Clinical Practice and Cases in Emergency Medicine. (2021).

Why is my poop green? What does this mean? (2022).