Normal stool is brown, and the shade can range from light tan to dark chocolate. This color comes from a pigment called stercobilin, which forms when bacteria in your intestines break down bile. As long as your stool falls somewhere in the brown spectrum, your digestive system is processing bile the way it should.
Why Stool Is Brown
Your liver produces bile, a yellow-green fluid that helps digest fats. As bile travels through your digestive tract, gut bacteria chemically transform it through several steps. First, they break bilirubin (a component of bile) down into colorless compounds. Then, when these compounds are exposed to air, they oxidize into stercobilin, the red-orange pigment that gives stool its characteristic brown color.
This process takes time. Food typically spends 24 to 72 hours moving through your system, and the longer bile has to be processed, the deeper brown the result. When something disrupts this timeline or interferes with bile production, your stool changes color.
Green Stool
Green stool is one of the most common color variations, and it’s usually harmless. The two main causes are diet and transit speed.
Spinach, kale, broccoli, and other green vegetables contain chlorophyll, which can tint your stool bright green if you eat enough of them. Pistachios, avocados, matcha, and various herbs do the same thing. Green food dyes from candy or frosting can also be the culprit.
The other common explanation is that food moved through your intestines faster than usual, often because of diarrhea. Bile starts out yellow-green. It only turns brown after bacteria have had time to fully process it. When transit speeds up, bile doesn’t get completely broken down, and the stool stays green. This is temporary and resolves once your digestion returns to its normal pace.
Yellow or Greasy Stool
Occasional yellow stool isn’t alarming, but stool that is consistently yellow, greasy, foul-smelling, and floats may signal a fat absorption problem called steatorrhea. This happens when your body can’t properly digest or absorb dietary fat, so the excess fat ends up in your stool.
Several conditions can cause this. If your pancreas doesn’t produce enough digestive enzymes (a problem linked to chronic pancreatitis, cystic fibrosis, or pancreatic cancer), fat passes through undigested. Celiac disease, Crohn’s disease, and small intestinal bacterial overgrowth can also impair fat absorption in the intestines themselves. Some antibiotics can temporarily tint stool yellow as well, which is a less concerning cause.
Pale, Clay, or White Stool
Pale or clay-colored stool is one of the more significant color changes because it means bile isn’t reaching your intestines. Since bile is what ultimately creates the brown pigment, its absence leaves stool looking like light clay or putty.
This happens when something blocks the bile ducts or when the liver isn’t producing enough bile. Gallstones are a common cause. Other possibilities include hepatitis (both viral and alcohol-related), biliary cirrhosis, tumors in the liver or pancreas, and narrowing of the bile ducts. Some medications can also cause pale stool. If your stool is consistently white or clay-colored, that warrants prompt medical attention because it points to a problem with your liver, gallbladder, or bile ducts.
Black Stool
Black stool has two very different explanations, one benign and one serious, and the texture is what separates them.
Iron supplements commonly turn stool dark green to black. Pepto-Bismol can make it jet black. Blueberries in large quantities, black licorice, and even mixtures of colorful candy dyes can darken stool significantly. In all these cases, the stool looks dark but has a normal consistency and smell.
The concerning version is called melena: stool that is jet black, tarry, sticky, and has a distinctly strong, foul odor. This appearance comes from blood that has been digested as it traveled through the upper gastrointestinal tract (the stomach or upper intestines). The longer blood spends in the digestive system, the darker and more pungent it becomes. If your black stool is sticky and unusually foul-smelling rather than simply dark, that’s a meaningful distinction.
Red or Bloody Stool
Bright red stool can come from food or from bleeding in the lower digestive tract. Beets are a classic dietary cause. A pigment called betanin gives beets their intense color and can make stool look alarmingly blood-red. Cherries, tomatoes, red food dye, and red gelatin can do the same.
When the red color is actually blood, it typically comes from the lower end of the digestive tract. Hemorrhoids are the most common source. Internal hemorrhoids are usually painless but tend to bleed, often showing up as bright red streaks on the stool or toilet paper. Anal fissures, which are small tears in the tissue lining the anus, are another frequent cause and tend to be painful. Colon polyps and inflammatory conditions further up in the colon can also produce red blood in stool.
Orange Stool
Orange stool is almost always dietary. Carrots, sweet potatoes, squash, and pumpkin are rich in beta-carotene, and eating plenty of them can tint your stool orange. Foods with orange or yellow artificial dyes have the same effect. This is harmless and clears up once the food works its way through your system.
Normal Colors for Baby Stool
Infant stool follows a completely different color chart than adult stool, and what’s normal changes rapidly in the first weeks of life. A newborn’s first bowel movements are meconium: a sticky, tar-like substance that’s dark green to black. This is expected and clears within a couple of days.
After that, feeding method determines what’s typical. Breastfed babies produce loose, mustard-yellow stool, sometimes with a seedy texture. Frothy green stool can occur in breastfed babies who switch breasts frequently. Formula-fed babies tend to have darker yellow stool that’s slightly firmer, and the iron in formula can turn it dark green.
Once solid foods are introduced, the color palette expands to include green, brown, and orange, depending on what the baby eats. As children get older, their stool gradually transitions to the adult brown range. The one color that’s always a red flag in infants is white or very pale stool, which can indicate a bile duct problem and should be evaluated quickly.
When Color Changes Matter
A single off-color stool after eating beets, taking iron supplements, or having a bout of diarrhea is rarely significant. The pattern matters more than any one instance. Color changes that persist for several days without an obvious dietary explanation are worth paying attention to, especially pale or clay-colored stool, persistent black tarry stool with a strong odor, or ongoing red blood mixed into the stool rather than just on the surface. These patterns suggest something beyond food is affecting your digestive process and benefit from evaluation.