Stool Color Chart: What Your Poop Color Means

Your stool is brown for a very specific biochemical reason. Hemoglobin from old red blood cells gets broken down into bilirubin, which your liver conjugates and secretes into bile. As bile moves through your intestines, bacteria convert it into stercobilin - the pigment responsible for that familiar brown color. When something disrupts this process, the color changes. And that change is information.

Most color shifts come down to what you ate yesterday. But some - particularly black, red, and white - can signal conditions that need medical attention quickly. Here's a breakdown of each color, what causes it, and when it actually matters.

Brown: The Baseline

Healthy stool is brown because of a chain reaction that starts in your spleen. Roughly 80% of bilirubin comes from the breakdown of hemoglobin in aging red blood cells. Your liver processes this bilirubin, conjugates it with glucuronic acid, and excretes it into bile. Once bile reaches the colon, gut bacteria convert the bilirubin into urobilinogen and stercobilinogen. These compounds oxidize into stercobilin, which gives stool its brown pigment.

The shade varies. Dark brown after coffee or red meat, lighter brown after a carb-heavy meal. All normal. The shade matters far less than a complete departure from brown territory.

Green Stool

Bile starts out green. It only turns brown after bacteria and enzymes have had enough time to chemically break it down as it moves through your intestines. When food passes through too quickly - during a bout of diarrhea, for instance - bile pigments stay in their original greenish state because bacteria never finish processing them.

The most common cause, though, is diet. Spinach, kale, broccoli, and anything with green food dye can turn stool convincingly green. Iron supplements can push the color toward dark green or even black-green.

Less common causes

Gallbladder removal can temporarily dump extra bile into the digestive tract, causing greenish diarrhea that typically resolves within a few weeks. Bile acid malabsorption (BAM) is another culprit - and an underdiagnosed one. At least 30% of people diagnosed with functional diarrhea may actually have BAM. Excess bile acids trigger the colon to secrete extra water, producing watery, greenish stools.

Bottom line: Green stool after a salad is nothing. Green stool with persistent diarrhea for more than a few days deserves a conversation with your doctor.

Yellow Stool

Occasional yellow stool from turmeric, sweet potatoes, or a high-fat meal is harmless. Persistent yellow stool is different. When it's also greasy, foul-smelling, and tends to float, the medical term is steatorrhea - excess fat in your stool that your body failed to absorb.

Fat absorption requires three things working together: bile acids from the liver, digestive enzymes from the pancreas, and a healthy intestinal lining to absorb the end products. A problem with any one of these can cause steatorrhea.

Conditions linked to yellow, fatty stool

• Celiac disease - an immune reaction to gluten that damages the absorptive villi in the small intestine. The proximal duodenum and jejunum take the worst hit, which is also where most fat absorption happens.
• Exocrine pancreatic insufficiency (EPI) - when the pancreas can't produce enough digestive enzymes. Chronic pancreatitis, often from long-term alcohol use or gallstone complications, is the leading cause. Cystic fibrosis and pancreatic cancer can also trigger it.
• Liver and bile duct diseases - conditions like cholestasis, primary biliary cholangitis, and cirrhosis can reduce bile production or block its delivery to the intestines.

Left untreated, chronic fat malabsorption leads to deficiencies in fat-soluble vitamins A, D, E, and K, along with weight loss and muscle wasting. If your stool has been yellow and greasy for more than a week or two, get it checked.

Orange Stool

Orange stool is almost always dietary. Beta-carotene - the pigment in carrots, sweet potatoes, squash, and pumpkin - can tint stool orange when consumed in large quantities. Food dyes, turmeric supplements, and the antibiotic rifampin can do the same.

You'd need to eat roughly 10 medium carrots a day for several weeks to see a noticeable effect, so this color is uncommon unless you're supplementing with beta-carotene or eating very large amounts of orange-pigmented foods. It's not a color that typically signals a medical problem on its own.

Black Stool

This is where color becomes clinically urgent. Black stool has two very different categories, and telling them apart matters.

Harmless causes

Iron supplements, bismuth subsalicylate (Pepto-Bismol), black licorice, and blueberries can all darken stool to near-black. The stool is dark but doesn't have a tarry consistency or particularly foul odor.

Melena - the one to worry about

Melena is black, tarry, sticky stool with a distinctive strong odor. It signals upper gastrointestinal bleeding - typically from the esophagus, stomach, or duodenum. Blood that has been digested by stomach acid and intestinal enzymes turns black as hemoglobin is converted to hematin. It takes as little as 50 mL of blood in the stomach to produce melena.

Common causes include peptic ulcers (responsible for about 37% of upper GI bleeds), esophageal or gastric varices (30%), Mallory-Weiss tears, and erosive gastritis. Upper GI bleeding has an annual incidence of 50 to 150 per 100,000 people, with a mortality rate between 2% and 10%.

If your stool is black, tarry, and foul-smelling - and you haven't taken iron or bismuth - treat it as a medical emergency.

Red or Maroon Stool

Blood in stool can range from bright red streaks on toilet paper to deep maroon mixed into the stool itself. The color roughly correlates with where the bleeding originates.

Bright red blood

Bright red blood usually comes from the lower GI tract - the colon, rectum, or anus. The most common cause in adults under 50 is hemorrhoids, followed by anal fissures. Blood from hemorrhoids typically coats the stool surface or appears on toilet paper rather than mixing into the stool itself.

But bright red blood isn't always benign. Diverticular disease accounts for over 40% of lower GI bleeds requiring hospitalization. Colon polyps and colorectal cancer also cause rectal bleeding, and one study found that cancer was still present in 2% of patients who had bleeding alongside hemorrhoids. A useful distinction: blood mixed into the stool suggests a colonic source, while blood only on the surface suggests a rectal or anal source.

Maroon stool

Darker, maroon-colored blood often originates from the right colon or small intestine. It's had more time in the digestive tract than bright red blood, but not enough to turn fully black. Causes include diverticular bleeding, vascular malformations, and inflammatory bowel disease. About 15% of hematochezia cases actually trace back to an upper GI source bleeding fast enough that the blood doesn't fully darken.

The American Cancer Society recommends colon cancer screening starting at age 45. Any persistent rectal bleeding should be evaluated regardless of age.

White, Clay, or Pale Stool

This color is always clinically significant. Stool turns pale when bilirubin can't reach the intestines. Without bilirubin, there's no stercobilin, and without stercobilin, there's no brown pigment. The result is white, gray, or clay-colored stool - sometimes called acholic stool.

The most common cause is biliary obstruction - a blockage in the bile ducts, most often from gallstones. Other causes include:

• Gallstones blocking the common bile duct - the single most prevalent cause
• Pancreatic cancer or bile duct cancer compressing the biliary system
• Hepatitis (viral, toxic, or alcohol-induced) impairing the liver's ability to produce bile
• Primary biliary cholangitis or primary sclerosing cholangitis - chronic inflammatory conditions that damage bile ducts over time
• Cirrhosis - advanced liver scarring from any cause

The classic warning triad is pale stools, dark urine, and jaundice (yellowing of the skin and eyes). Together, these point to conjugated bilirubin building up in the blood because it has nowhere to go. If you notice this combination, contact a healthcare provider right away. Untreated biliary obstruction can progress to infection, liver damage, and cirrhosis.

Foods and Medications That Change Stool Color

Before assuming the worst, run through this mental checklist. Plenty of everyday items can cause temporary color changes that mean nothing medically:

• Green: Spinach, kale, broccoli, green food dye, iron supplements
• Orange: Carrots, sweet potatoes, squash, turmeric, beta-carotene supplements
• Red: Beets, tomato soup, red gelatin, cranberries, red food dye
• Black: Iron supplements, Pepto-Bismol (bismuth), black licorice, blueberries
• Yellow: Turmeric, high-fat meals, food with yellow dye

The key question: did it resolve within a day or two after you stopped eating the suspect food? If yes, you have your answer. If not, something else is going on. For a complete picture, stool shape matters alongside color - our interactive Bristol chart covers the form side.

When to See a Doctor

Most stool color changes are temporary and diet-related. But these warrant prompt medical attention:

• Black, tarry stool that you can't attribute to iron supplements or bismuth
• Bright red or maroon blood in or on your stool, especially if persistent or heavy
• White, clay, or pale stool - particularly with dark urine and jaundice
• Persistent yellow, greasy stool with weight loss or bloating
• Any color change lasting more than two weeks without a clear dietary explanation
• Color changes accompanied by fever, severe abdominal pain, vomiting, or dizziness

Upper GI bleeding accounts for roughly 40% of hospital admissions for gastrointestinal bleeding in the United States. Early detection makes a significant difference in outcomes, so don't wait out symptoms that look serious.

Why Tracking Stool Color Matters

A single unusual bowel movement is a data point. A pattern is diagnostic information. That one green stool after a spinach smoothie tells you nothing useful. But if you're consistently seeing yellow, greasy stools every few days for a month, that's a pattern your doctor needs to hear about - and ideally, see documented.

The challenge is memory. Most people can't accurately recall what their stool looked like three weeks ago, let alone describe a trend. That's the same reason gastroenterologists recommend keeping a stool diary: written records beat memory every time, especially for something you'd rather not think about more than you have to.