Why is my poop green?
General information only. This article explains the basics and is not medical advice. For anything about your own health, talk to a doctor or other qualified professional.
Quick answer
Green poop is usually harmless. It’s most often caused by eating green foods like spinach and kale, green or blue food coloring, iron supplements, or food passing through the gut too quickly (for example with diarrhea), so bile doesn’t have time to turn brown. Bright, multicolored “rainbow” poop is almost always from food dyes.
Poop is normally brown because of bile, a greenish-yellow fluid from the liver that changes color as it moves through the intestines. Anything that changes what you eat, or how fast food travels, can change the color.
What stool colors can mean
| Color | Common harmless causes | When to ask a doctor |
|---|---|---|
| Green | Leafy greens, food dye, fast transit | If it lasts with diarrhea for more than a few days |
| Rainbow / bright colors | Brightly colored candy, cereal, frosting, drinks | Rarely a concern |
| Yellow, greasy | Fatty meal | If it’s frequent, smells very bad or floats often |
| Red | Beets, red food dye, tomato juice | If it looks like blood, see a doctor promptly |
| Black | Iron supplements, bismuth stomach remedies, licorice | Black, tarry stool without these causes needs urgent care |
| Pale, white or clay-colored | Some medicines | Can signal a bile problem; see a doctor |
How long does color change last?
Color changes from food usually last a day or two. If you can link the color to something you ate, it’s very likely nothing to worry about.
When to get medical advice
Health sources advise seeing a doctor if an unusual color lasts more than a few days with no clear cause, or comes with stomach pain, fever, diarrhea, weight loss, or signs of blood. Seek urgent help for black, tarry stools or large amounts of blood.
Stomach discomfort often goes along with changes in poop; see why your stomach might hurt.
Sources
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