Stool color isn’t something you think about every day, but it’s something worth paying attention to, especially if you notice anything “off” with how your stool looks. Stool color also matters because it can help you better understand the state of your digestive health and overall health.
We connected with John “Jack” B. Doyle, MD, a gastroenterologist at Columbia University Irving Medical Center, to answer common questions about stool color, including how to identify healthy stool color, abnormal stool color, and when to see a doctor about stool color.
What Is a Normal Stool Color?
Most people know that stool is normally a brownish color, and you may feel distressed if you notice variations in your stool color. But Dr. Doyle assures that brown isn’t the only normal color.
“There’s a wide range of normal stool colors,” he explains. “Obviously, most of them are in the realm of brown, but they can be yellow and they can be green.”
Most stool colors don’t have much clinical significance, according to Dr. Doyle, and it’s normal to have stool that changes color from one bowel movement to another.
“Gastroenterologists don’t put a huge stock into it when someone says, ‘My stool is yellow,’ or ‘I saw some specks of green in it,’” Dr. Doyle says, adding that all shades of brown, yellow, and green are considered in the realm of normal.
Stool Color Chart: What Different Colors Mean
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Stool Color |
What You Should Know/Potential Causes |
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Brown |
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Green |
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Yellow |
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Black |
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Red |
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White, pale, or clay-colored stool |
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Common Stool Colors and Their Causes
Stool color isn’t always the same, and most changes in color are perfectly normal. Here’s what to know about the various causes of stool color:
- Brown: The Healthy Standard. Brown is usually considered the most “normal” color of stool. It gets this color when your liver releases bile salts into your stool.
- Green: Diet or Rapid Transit. Green can be a variation of normal stool color. Green stool causes include eating lots of veggies, like kale and spinach. Fast-moving stool, or diarrhea, can also cause greenish stool.
- Yellow: Fat Absorption Issues. Yellow stool is usually just a normal variation of brown stool. Less commonly, yellow stool causes can include a very high-fat diet or an issue with fat absorption from conditions like pancreatitis, liver disease, or celiac disease.
- Black: Food, Supplements, or Bleeding. Seeing dark or blackish stool can be scary. Most of the time, black stool causes stem from medication you’re taking, such as an iron supplement. Doctors get concerned when the stool is jet black and there’s a change in texture, “where it kind of looks like tar almost, very goopy and black,” Dr. Doyle describes. This appearance can be a sign of blood loss higher up in the digestive tract, like the stomach or the first part of the small intestine, he explains.
- Red: Foods or Lower GI Bleeding. Red stool causes can be something as innocent as red food dye or beets, both of which can cause your stool to take on a reddish tinge. The concern is when you see bright red blood in your stool or in the toilet, Dr. Doyle says. “That could be a sign of blood loss from the GI tract, most likely kind of lower down in the GI tract,” he says.
- Pale, White, or Clay-Colored: Bile Duct or Liver Issues. While it isn’t seen often, pale or clay-colored stool “can be a sign that bile is not reaching your GI tract, because bile is what gives stool its brown color,” Dr. Doyle explains. “If there’s no brown color whatsoever, sometimes that can be indicative of a blockage in the pipe that supplies bile to the GI tract.”
Other Influences on Stool Color
Sometimes medications, supplements, or foods can change your stool color. Iron is the most common one—it can turn your stool dark brown or black. “Most providers who prescribe that will tell patients that it’s not unexpected for your stool to appear very, very dark,” Dr. Doyle says.
But it’s not just iron-only supplements that have this effect. Any supplement with iron in it, including multivitamins, has the potential to darken your stool. The digestive medication Pepto-Bismol also can cause stool to be dark in color, Dr. Doyle says.
Eating large amounts of green vegetables can turn your stool a little greenish, he says, whereas eating beets can cause a little bit of reddish tinge to your stool, but it doesn’t usually look like obvious blood.
The effects of food dyes on stool are “less well studied, so it’s hard to make a blanket statement about them,” Dr. Doyle says. He notes that something like red food dye, which travels through your GI tract very quickly, often comes out in stool and can sometimes be mistaken for blood. However, “Blood usually looks very distinct from just a tinge of red,” Dr. Doyle explains. “If it’s bright red blood, most people can identify it pretty quickly.”
If you know you’ve eaten something or taken a medication that is causing your stool to be blackish or reddish, you don’t need to be alarmed. But any new symptom—especially blood in your stool—should prompt a call to your doctor.
When to Worry: Warning Signs and When to See a Doctor
Most of the time, variations in stool color aren’t something to stress about too much. Your stool can be brown, yellow, or green and be just fine. It can be normal for your stool to be blackish, if you are taking iron supplements.
So, when to see a doctor about stool color? Dr. Doyle points to two key warning signs that should prompt a call to your healthcare provider, as they may indicate blood somewhere in your GI tract. “So, either bright red blood in the stool that can usually be seen in the toilet, like turning the toilet red or pink,” he describes. “Or, jet black tarry stool, assuming that you’re not taking iron pills or Pepto-Bismol. Those would be the two stool color changes that should prompt a GI visit.”
Furthermore, contact your physician if you have white stool, a symptom Dr. Doyle describes as “extremely rare.” White stool indicates an issue with the drainage system of your liver, pancreas and gallbladder. However, people with this problem usually see other signs before experiencing white stool, such as yellowing of the eyes, dark urine, night sweats, weight loss, and fatigue.
Still, white stool is “another color, besides red or black, that we think of as indicating that something could be wrong,” Dr. Doyle emphasizes.
Stool Consistency: What It Tells You
Like stool color, stool consistency (shape and texture) has many variations of normal. “The average person has wide variety in their stool consistency and form throughout a given week,” Dr. Doyle says. “Common things like coffee can affect it, or something you ate the day before.”
Sometimes the consistency of your stool can tell you about the general state of your digestive health. For example, very hard stool that forms little balls like deer pellets or rabbit poop are signs of severe constipation, Dr. Doyle says. On the other end of the spectrum is diarrhea, or loose, watery stools. Diarrhea that lasts a few days can indicate that you’re under the weather, are experiencing a food sensitivity, or that you are reacting to a medication. Chronic diarrhea may be a sign of a condition like irritable bowel syndrome, ulcerative colitis, or Crohn’s disease.
Overall, stool consistency is rarely an emergency, but ongoing changes in consistency are “something you probably talk about with a gastroenterologist,” Dr. Doyle advises.
The Bottom Line
Noticing any stool color besides the familiar brownish shade can be alarming. But there’s a wide spectrum of normal when it comes to stool color, and it’s only really blood in your stool, tarry black stool, or whitish stool that are reason for concern.
That being said, you shouldn’t hesitate to reach out to your healthcare provider if you notice any new or concerning changes in stool color.
