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Stool Colors for Adults: What Do Different Stool Colors Mean?

Concerned about the color of your poop? Learn about what causes abnormal stool color, what different stool colors mean, and when to follow up with a medical professional about discolored stool.

Taking a look at your own poop in the toilet may not be most pleasant part of your day, but it's actually a very effective way to monitor your overall health. Stool isn't always just plain brown, especially when there's something abnormal going on in your body.

Here is some information about what different colors of stool may mean and what health issues they may be signs of. We'll look at the reasons for dark stool in adults, what causes light color stool, and other color variations that can appear when you take a look before you flush.

What the color of your poop says about your health

Poop comes in various shapes and colors, but what you excrete out can reveal many different things about your physical and metal health. For instance, it's important for people with Crohn's disease to check their stool regularly to note changes in their condition. Stool samples also indicate the types of bacteria that live in your gut, microbes that may lead to future health issues, and changes in your mood. Stool is also affected by your regular diet and even certain foods that you eat on an occasional basis.

In addition to stool color, the texture and consistency of your poop is also a window to your health. Poop that is hard or that appears in small pellet form may mean that you are dehydrated or aren't eating enough fiber-rich foods. Loose stool that isn't quite diarrhea indicates that your digestive system is sensitive to something that you ate. Very thin poop may just be a result of your diet, but it could also be an early warning sign of colon cancer that needs to be checked out. And if your stool smells worse than usual, this is often a sign that the stool is staying in the body longer than normal or that you are constipated.

Identifying Discolored Stool

Normal, healthy stool is light brown to dark brown in color. It also tends to be in a banana shape, about a foot long, and approximately the consistency of toothpaste. Please don't let this description ruin fruit or dental hygiene for you!

Each time you pass a bowel movement, take a quick look at the toilet bowel to see if anything abnormal stands out to you. Think about the foods you've recently eaten, medications you've been taking, and call a doctor if you have concerns about the color of your poop.

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Different types of abnormal stool color

In the sections that follow, we're taking a closer look at the specific colors that stool can be and what those colors mean.

Dark Stool in Adults: What Causes Your Stool to Be Black?

Dark stool in adults is quite common, but stool that is black can be a cause for concern. That's because this type of discolored stool can mean that you are experiencing upper gastrointestinal tract bleeding. Stool that is truly black may also have a tarry appearance and a very foul smell. Tar-like black stool may indicate ulcers or acid reflux that is causing bleeding sores in the esophagus.

In rare cases, it is possible to experience black stool after swallowing a large amount of blood from a mouth injury or even a nosebleed. Other conditions associated with black-tar colored stools and constipation are irritable bowel syndrome, colon cancer, peptic ulcer, anal fissure, and kidney infection.

Eating large amounts of black licorice may also cause stool to become black, as well as iron supplements and anti-diarrheal drugs like Pepto-Bismol. A gastrointestinal endoscopy may be needed to test for bleeding and stop the GI tract from continuing to bleed.

What Causes Your Stool to Be Green?

Some greenness in the stool is considered to be normal because bile is a greenish fluid that helps to digest fats in the body. Bile travels through the gastrointestinal tract and is affected by enzymes to change much of that color from green to brown.

Green poop often means that food that you eat is traveling through the large intestines at a rate that is faster than normal. In this instance, bile does not have enough time to break down, so the poop appears green in color. Green poop may be a result of diarrhea because the transit time is shortened when this condition is present.

As far as diet goes, your stool may look mildly green if you have been eating lots of leafy green vegetables or foods that have been dyed with green food coloring. Iron supplements also have a tendency to turn poop green.

What Causes Light Colored Stool?

The answer to what cause light colored stool or stool that appears white in color is usually a lack of bile. Unlike green stool, white or light-colored stool can be caused by an obstruction of a bile duct that isn't letting a proper amount of bile through the digestive system.

Without an adequate amount of bile, stool loses its natural color and appears pale. Light colored stool is often an early warning sign of liver disease, pancreatic cancer, gallstones, a tumor, or biliary atresia.

Also, light colored stool may be caused by Pepto-Bismol and other drugs used to control diarrhea. This is typically true only when the medications are taken in large doses or consumed for a long period of time.

What Causes Bright Red Stool?

There are quite a few reasons why your stool can appear bright red in color. This color can indicate that you have hemorrhoids or another condition that is causing lower intestinal tract bleeding. This bleeding often occurs in the rectum or large intestines to produce bright red poop.

Diverticular bleeding, tumors, and inflammatory bowel disease are other causes for bright red poop. It can also be caused by ulcerative colitis, Crohn's disease, and biological miscommunications between the veins and arteries in the intestinal wall.

Consuming beets, tomato juice, cherries, or cranberries can also create a reddish stool color, but this is typically a milder color without other symptoms. As with black stool, patients who seek care for bright red stool may need to take an endoscopy to address a potential bleeding disorder.

What Causes Maroon-Colored Stool?

Maroon, or reddish-brown stool may also indicate upper GI tract bleeding. The bleeding associated with this color often occurs in the stomach or esophagus. This color of stool may not seem as alarming as a bright red stool, but the cause may still be serious. A maroon color is the result of partial digestion in the intestines, and the shade of the color is determined by how quickly the blood moves through the intestines.

Spotlight on: yellow stool

A spotlight section on yellow stool. Skip to the next section if not relevant.

What Causes Yellow-Colored Stool?

Stool also can have a yellow appearance, which is often accompanied by a bad odor and a greasy texture (otherwise known as steatorrhea). This means that there is a large amount of fat in the stool. Fat will collect in the stool when it is not absorbed properly in the body. In other words, some type of malabsorption problem exists. In most people, food is digested and its building blocks or nutrients (fats, proteins, carbohydrates, vitamins and minerals) are readily absorbed in the bloodstream--a job mainly covered by the small intestine. The lining of the small intestine is made up of tiny projections called villi. Villi and their even tinier counterparts--microvilli--create significant surface area for the absorption of essential nutrients. Malabsorption happens when something (physical disorder, surgical procedure or infection) interferes with the digestion of food or the absorption of nutrients.

Malabsorption can cause all sorts of problems. In general, people with malabsorption often have difficulty maintaining their usual weight or actually lose weight despite their consuming an adequate amount of food. Malabsorption symptoms depend on the whatever the deficiency is. For example, fat malabsorption can lead to that unattractive yellow poop. Protein deficiency can lead to fluid accumulation anywhere in the body. Iron or folate (folic acid) deficiencies can lead to weakness and fatigue due to anemia. These are just some examples of various types of nutrient deficiencies caused by malabsorption. Below are some types of problems associated with inadequate fat absorption.


There are a number of infections that can cause malabsorption. These infections can either be bacterial, viral or parasitic in nature. One of the parasitic infections is giardiasis (also called giardia infection), which is caused by a microscopic waterborne parasite. It's one of the most common causes of waterborne diseases in the United Sates. The parasite is found throughout the world, particularly in places with poor sanitation and unclean water. However, it's also found in swimming pools, water parks, whirlpools, streams, lakes, ponds, cisterns, wells and municipal water supplies. And it can be transmitted through food and from person to person. Besides yellow poop, giardiasis can also cause watery, often foul-smelling diarrhea, fatigue, abdominal cramps or bloating, flatulence, weight loss and nausea. If any of these symptoms last more than a week, contact your doctor.

Surgical Procedures

Sometimes problems with the gastrointestinal tract (structural blockages or tumors, for example) are best solved through surgical intervention, such as removal of part of the tract. This can cause problems with fat absorption, as well as malabsorption of other nutrients. The presence of yellow stools is a sign of the former. Bariatric surgery (performed on the intestines or stomach to induce weight loss) also may cause inadequate fat absorption. Surgery on the liver (for cancer or cirrhosis, for example) or the stomach also may lead to fat malabsorption. If you've undergone such a surgical procedure and are experiencing yellow stools, it's best to inform your doctor as soon as possible.

Gastroesophageal Reflux (GER) and Gastroesophageal Reflux Disease (GERD)

GER results when the food that you eat, instead of staying in the stomach for part of the digestion process before continuing on its normal way, backs up into your esophagus. Acid reflux, commonly called heartburn" is the result. GERD is a long-lasting form of GER, and as such, is more serious. It can cause nutrients to pass too quickly through the gastrointestinal system, leading to fat malabsorption and yellow poop. Contact your doctor if you think you might be experiencing GERD.


We all know that different parts of our body are connected—just think of that children's song, "Dem Bones" ("the hip bone's connected to the back bone, the back bone's connected to the neck bone……."). But most people don't realize that the brain and the gastrointestinal system are also intimately connected in what's called the gut-brain connection. In other words, gastrointestinal distress can send signals to the brain just as brain distress can send signals to the gut. In the latter case, this means that stress can lead to malabsorption. When stress levels are high enough, the fight or flight response is triggered, leading to disruptive changes in the way that nutrients pass through the digestive system. If you feel that you are suffering from stress, you might experience yellow stools in addition to sadness, depression, sleep problems, headache, irritability, forgetfulness, restlessness, anxiety or lack of focus or motivation. Stress can be helped by psychotherapy options (such as cognitive behavioral therapy, relaxation therapy or hypnosis) or some lifestyle changes (such as regular physical activity, socializing or setting aside time for hobbies). If you think you may be suffering from stress, it's best to contact your doctor.

Celiac Disease

Celiac disease—a hereditary disease--causes damage to the small intestine because of the person's inability to process gluten (a protein found in wheat, barley and rye). In these individuals, the gluten causes the immune system to produce certain antibodies that flatten the small intestine's villi, thus leading to malabsorption. In addition to yellow stools, symptoms can include diarrhea, weight loss, anemia, osteoporosis (bone density loss), osteopenia (bone mass loss), mouth sores or an inflamed tongue. Some people with celiac disease, however, have symptoms so mild that they don't notice them or even no symptoms at all. Celiac disease is treated by adherence to a gluten-free diet. In some cases, people with celiac disease are advised by their doctors to take vitamin and mineral supplements such as folate and iron. Celiac disease increases the risk of certain digestive tract cancers, such as lymphoma of the small intestine. You should inform your doctor if you have a family history of celiac disease.

There are a number of quite serious diseases that are associated with yellow stool, including chronic pancreatitis, liver cancer, cystic fibrosis and pancreatic cancer. Below is information regarding these conditions.


This condition means that the pancreas, a long, flat gland behind the stomach in the upper abdomen, is inflamed. In chronic pancreatitis, the inflammation lasts many years and severely hinders the pancreas from doing its job, which is producing enzymes that help digestions and hormones that help regulate the body's processing of sugar (glucose). Besides smelly yellow stools, it can cause weight loss and upper abdominal pain. Chronic pancreatitis can be life-threatening and is a risk factor for pancreatic cancer. Contact your doctor so that proper diagnostic tests and treatment can be started.

Cystic Fibrosis (CF)

CF is a hereditary disease that causes mucus, sweat and digestive juices to be thick and sticky rather than thin and slippery. These secretions then block ducts, tubes and passageways in the lungs, pancreas, intestines, liver and gallbladder. When these blockages occur in any of these last four areas, fat malabsorption can result. This can be treated with supplements of pancreatic enzymes and vitamins. CF is diagnosed within the first month of life as newborn testing of the disease is mandatory in every state in the United States.


Yellow stool may occur as a result of various tumors that affect the gall bladder, liver, bile ducts or pancreas. The first three items are impacted by the body's inability to effectively produce enough bile, an essential part of the digestive process. Gallstones, which are masses of cholesterol, are noncancerous but can have a deleterious effect on bile production. In pancreatic cancer, the pancreas is unable to effectively produce the digestive enzymes necessary for optimum nutritional absorption. In addition to surgery, other therapies (such as chemotherapy or radiation) are needed to combat these malignancies.

Common questions asked about the color of your poop

Now that you have a basic understanding of what causes abnormal stool color and what the color of your poop may mean, let's take a look at some of the most common questions people ask about their stools.

Can green poop be a sign of infection?

This is another common question with green poop, and it can be caused by an infection in the body. The most common infections that cause green stool are salmonella, a bacterium, and giardia, which is a parasite. If one of these types of infections is causing your green poop, it will usually be accompanied by fever, diarrhea, and severe abdominal cramps.

Why is my poop green when I'm pregnant?

While green poop may be a sign of a serious medical condition, it's often very normal and common during pregnancy. Pregnant women often take prenatal supplements that contain iron, and iron can cause discolored stool. In an effort to eat healthier, pregnant women may be consuming more leafy green vegetables that turn their poop green. Pregnant women are also undergoing many totally natural hormonal changes, which may result in differently colored stool.

Why does my green poop smell like sulfur?

What you eat has a big impact on the color of your stool and how it smells. Many green-colored vegetables contain sulfur, including kale, broccoli, Brussels sprouts, and cabbage. This may explain why green poop smells like sulfur. Cruciferous vegetables take more energy to digest, sending your digestive system into overtime and increasing the amount of gasses produced that cause strong odors.

When should you seek medical attention for dark brown stool?

Normal stool is typically light brown to dark brown, so you may not need to be concerned about dark brown stool at all. But if your stool begins to look black and tar-like or contain blood, it is highly recommended to seek medical attention immediately because internal bleeding may be causing the discoloration.

Why do I have dark brown stool when I'm constipated?

In addition to gastrointestinal bleeding, dark stool in adults can be a result of constipation. Constipation is defined as having less than three bowel movements in a week, and it's often accompanied by abdominal pain and hard stools when they are finally released.

Do certain medications cause dark brown stool?

Yes, some medications can cause dark stools in adults as a side effect. Also, Pepto-Bismol and other medications containing bismuth can have this effect. Iron supplements are known to cause discolored stool as well.

Why do I have dark brown stool with no pain?

Just because a stool is dark brown doesn't mean that it is the sign of a health disorder. Some dark brown stools are totally normal and therefore cause no pain or other symptoms. You may also have no pain if the dark brown stools are caused by foods that you have eaten or due to food coloring additives.

Why do I have dark brown stool before my period?

When the stool is dark, it often means that blood is entering the along the intestinal tract. If you are experiencing vaginal bleeding with bowel movements, it is a good idea to contact your doctor for a checkup. Dark brown stool is usually normal, but tarry and black stool is not. On the flip side, some women experience noticeably lighter brown stool before their periods.

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