Healthy poop is brown, typically a medium shade ranging from light to dark brown. That color comes from a pigment called stercobilin, which forms when your liver’s bile salts get broken down by bacteria in your gut during digestion. As long as your stool falls somewhere in the brown spectrum, your digestive system is working as expected. Other colors aren’t always a problem, but some are worth paying attention to.
Why Brown Is the Standard
Your liver constantly produces bile, a greenish-yellow fluid that helps you digest fats. As bile travels through your intestines, gut bacteria chemically transform it into stercobilin, a brown pigment that gives stool its characteristic color. The exact shade depends on what you’ve eaten, how much water you’ve had, and how long food spent moving through your system. A slightly lighter or darker brown from day to day is completely normal.
Green Stool
Green poop has two main causes, and neither is usually concerning. The first is diet. Spinach, kale, broccoli, avocados, pistachios, herbs, and matcha all contain chlorophyll, the same pigment that makes plants green, and eating enough of these can turn your stool bright green. Green food coloring in drink mixes, ice pops, or candy does the same thing. Iron supplements are another common culprit.
The second cause is speed. When food moves through your intestines faster than normal, such as during a bout of diarrhea, bile doesn’t have time to fully break down into that brown pigment. The result is stool that still carries bile’s original green tint. If green stool shows up for a day or two and you can trace it to something you ate or a stomach bug, it’s not a red flag.
Yellow or Greasy Stool
Stool that’s yellow, pale, greasy, and unusually foul-smelling can signal fat malabsorption, meaning your digestive system isn’t breaking down or absorbing fats properly. This type of stool tends to be looser than normal and may float. Celiac disease and giardiasis (a common intestinal parasite infection) are two well-known causes. If yellow, greasy stools persist for more than a few days, that pattern is worth investigating, as it often points to a specific underlying condition rather than a passing issue.
Pale, Clay-Colored, or White Stool
Stool that looks pale, chalky, or clay-colored indicates a lack of bile. Since bile salts are what give stool its brown color in the first place, anything that reduces bile production or blocks its flow will leave stool looking washed out. Possible causes include gallstones blocking the bile ducts, liver infections like hepatitis, biliary cirrhosis, and tumors affecting the liver, bile ducts, or pancreas. Certain medications can also temporarily cause pale stools.
This color is one of the more medically significant changes because it consistently points to a problem with the liver or biliary system rather than something dietary. Pale stool that lasts more than one or two bowel movements deserves medical attention.
Red Stool
Red stool can look alarming, but it doesn’t always mean bleeding. Beets are notorious for turning stool (and urine) a vivid red. Cherries, tomatoes, red food coloring, and other deeply pigmented red foods can have the same effect.
When the red is actually blood, the shade matters. Bright red blood typically means the source is lower in the digestive tract: the colon, rectum, or anus. Hemorrhoids are a common and relatively minor cause. Dark red or maroon-colored blood suggests bleeding higher up, in the upper colon or small intestine. If you see red and you haven’t eaten beets or red-colored foods recently, that warrants a closer look, especially if it’s accompanied by pain, dizziness, or repeated episodes.
Black Stool
Black stool falls into two very different categories. The harmless kind comes from foods and supplements: black licorice, blueberries (which can also turn stool dark blue or green), iron pills, activated charcoal, and bismuth-based medications like Pepto-Bismol. Even eating a lot of rainbow-colored candy can mix into a dark, nearly black shade. In these cases, the stool looks dark but doesn’t have an unusual smell or sticky texture.
The concerning kind is called melena. It’s black, tarry, sticky, and has a distinctly foul odor. Melena indicates bleeding in the upper digestive tract, usually the stomach, esophagus, or the first section of the small intestine. Peptic ulcers are the most common cause. Other possibilities include inflammation of the stomach lining, tears in the esophagus from violent vomiting, or enlarged veins in the esophagus related to liver disease. The difference between food-related black stool and melena is usually obvious: melena has a tar-like consistency that’s hard to miss.
Orange Stool
Orange stool is almost always dietary. Carrots, sweet potatoes, squash, and pumpkin are all rich in beta-carotene, a pigment that can tint your stool orange when you eat enough of them. This is harmless and resolves on its own once you stop eating large amounts of these foods.
What’s Normal for Babies
Infant stool follows a different color timeline than adult stool, and new parents often find it surprising. A newborn’s first bowel movements consist of meconium, a dark green to black, sticky, tar-like substance that’s completely normal. This clears within the first couple of days.
Breastfed babies typically produce mustard-yellow stool that’s loose and slightly runny. Formula-fed babies tend to have darker yellow stool that’s a bit firmer. Formula-fed infants may also produce dark green stool due to the iron content in formula, which is nothing to worry about. The one color that’s a concern in infants is the same as in adults: white, pale, or clay-colored stool, which can indicate a bile flow problem and should be evaluated promptly.
Texture Matters Too
Color is only part of the picture. The Bristol Stool Scale, a widely used medical reference, classifies stool into seven types based on shape and consistency. Types 3 and 4, sausage-shaped with some surface cracks or smooth and soft, are considered ideal. Types 1 and 2 (hard lumps or lumpy sausages) suggest constipation. Types 6 and 7 (mushy or watery) indicate diarrhea. A brown stool that’s consistently very hard or very loose can signal a digestive issue even though the color looks fine.
When Color Changes Are Temporary
Most stool color shifts last a day or two and trace directly back to something you ate. If you had a big beet salad, a green smoothie loaded with spinach, or took a dose of Pepto-Bismol, your stool may look unusual at the next bathroom visit. That’s your digestive system processing pigments, not a sign of disease. The key distinction is duration: a one-off color change after a specific meal is different from a persistent change over several days with no dietary explanation. Persistent pale, black (tarry), or red-tinged stool that you can’t connect to food deserves medical evaluation.