Why is my poop green?
Last updated September 3, 2026.
Green poop is usually bile that did not have time to turn brown - because your gut moved fast for a few days - or food that arrived green: leafy vegetables, food colouring, or iron supplements. MedlinePlus confirms bile salts give stool its brown colour and that fast transit causes diarrhoea. Alone and brief, it needs nothing. Pymander is a free AI doctor, 24/7 by text, and can help you read the picture.
What to do
- Replay the last 3 days: spinach binges, dyed drinks, iron tablets, or a laxative explain most cases.
- Think about speed: a stomach bug or antibiotics speed transit and skip the browning.
- Watch for real warning colours: clay-pale, black and tarry, or red with blood.
- Green diarrhoea past a few days, with fever or weight loss? See a GP.
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