The color of your stool is primarily determined by bile, a yellowish-green fluid produced by your liver. As bile travels through your digestive tract, it is broken down by enzymes and bacteria, gradually turning brown. Any shift in this process—or the presence of other substances—can change the color of your poop, offering a surprising window into your health.
Here is a guide to what different colors may be indicating:
| Stool Color | Likely Cause (Dietary) | Potential Health Concern (If Persistent) |
| Brown (All Shades) | Normal & Healthy. The color is due to adequate bilirubin and bile being processed. | None. This is the ideal range. |
| Green | High intake of leafy green vegetables (spinach, kale), green food coloring, or iron supplements. | Rapid Transit/Diarrhea: Food is moving through the large intestine too quickly, meaning the bile doesn’t have enough time to break down and change to brown. May indicate an infection or IBS. |
| Yellow, Greasy, & Foul-Smelling | Excessive consumption of high-fat foods, carrots, or sweet potatoes (beta-carotene). | Malabsorption: Excess fat in the stool (steatorrhea) due to poor absorption. May indicate a problem with the small intestine (e.g., Celiac disease) or the pancreas (e.g., chronic pancreatitis). |
| Black or Tarry | Iron supplements, Pepto-Bismol (bismuth subsalicylate), black licorice, or blueberries. | Upper Gastrointestinal (GI) Bleeding: The blood is old and has been digested in the stomach or upper small intestine (e.g., bleeding ulcers). This is a medical concern. |
| Bright Red | Beets, cranberries, red gelatin/dyes, tomato juice. | Lower GI Bleeding: The blood is fresh, usually from the lower large intestine or rectum (e.g., hemorrhoids, anal fissures, diverticulosis, or rarely, tumors). |
| Pale, White, or Clay-Colored | Large doses of certain anti-diarrheal medications (like bismuth), or a barium meal/enema for imaging. | Lack of Bile: May indicate a blockage of the bile duct due to gallstones, or a problem with the liver (e.g., hepatitis, cirrhosis) or pancreas. This requires immediate medical attention. |
When to Call Your Doctor IMMEDIATELY
While diet often causes harmless color changes, there are three colors that should prompt you to call a healthcare provider right away, especially if the color is persistent and cannot be explained by food or medication:
- Black and Tarry: Suggests upper GI bleeding.
- Bright Red: Suggests lower GI bleeding.
- Pale, White, or Clay-Colored: Suggests a potentially serious issue with the liver, gallbladder, or bile ducts.