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🟤 Medium to Dark Brown
Normal
The gold standard. Brown color comes from bilirubin, a byproduct of red blood cell breakdown processed by your liver and bile. Medium-to-dark brown stool indicates healthy transit and normal bile processing.
🟢 Green
Usually harmless
Most often caused by leafy greens, green food dye, or iron supplements. Can also indicate fast transit — stool moving too quickly for bile to fully break down. Green stool during a diarrhea episode is common and not alarming.
🟡 Yellow / Pale Yellow
Watch if persistent
Can indicate excess fat in stool (steatorrhea), often caused by celiac disease, exocrine pancreatic insufficiency, or giardia. If yellow stool is also greasy, foul-smelling, and floats, see a doctor. Occasional pale yellow from carrots or sweet potatoes is benign.
🔴 Bright Red
Investigate — don't ignore
Suggests bleeding in the lower digestive tract — most commonly hemorrhoids or an anal fissure (usually benign), but also potentially colorectal polyps, diverticular disease, or colitis. Always confirm the source with a doctor, especially with no obvious explanation like beets.
⚫ Black / Tarry
Urgent — see a doctor
Tarry, foul-smelling black stool (melena) indicates bleeding in the upper GI tract — stomach, esophagus, or small intestine. Can be caused by a peptic ulcer or esophageal varices. Iron supplements and bismuth also cause black stool but without the tarry consistency.
⬜ White / Pale / Clay
See a doctor
White or clay-colored stool means bile is absent — bile gives stool its brown color. This can indicate a blockage in the bile ducts (gallstones, stricture, or tumor) or liver disease. This is a red flag worth investigating promptly.
🟠 Orange
Usually diet-related
Most often follows eating large amounts of orange or red foods — carrots, sweet potatoes, squash, or foods with annatto dye. If persistent without a dietary explanation, can occasionally indicate bile duct issues or malabsorption.
🟣 Purple / Very Dark Red
Often food-related, sometimes not
Most commonly follows eating beets, blueberries, or blackberries. Without a dietary explanation, dark red stool can indicate lower GI bleeding and should be evaluated.
The golden rule
A single unusual stool color is almost always diet or hydration-related. A consistently abnormal color over multiple days, especially with other symptoms (pain, urgency, weight loss, fatigue), is worth discussing with a doctor. When in doubt — and especially with black tarry or clay-white stool — don't wait.