What Causes Dark Brown Stool or Different Stool Colors? Your Symptoms Explained

Dark brown stool is considered a normal color for a bowel movement, however very dark brown poop can indicated diet changes from certain foods or iron supplements, or mild internal bleeding located in the upper digestive tract. Dark brown stool can also indicate dehydration, usually after drinking alcohol, or infection. Read below for more causes and treatment options.

Dark Brown Poop Symptoms Explained

Dark brown stool is generally considered normal. However, "dark brown" is open to interpretation and there are variations in color that may or may not mean there is a problem. Don't hesitate to ask your doctor any questions about the appearance of your stool. The color of stool can sometimes be the first sign of something wrong and is often what prompts a person to see their doctor or even go to an emergency room. Stool is also known as feces.

Other characteristics of dark brown stool

Normal stool is medium to dark brown, about the color of milk chocolate. Other factors that play into stool color include the following.

  • The health of your diet: Nutrients necessary for digestion are likely being consumed if your stool is a medium-brown color.
  • Bilirubin levels: Bilirubin is a component of bile, which aids in the digestion of fats. Bilirubin gives the stool its dark to medium-brown color and means that digestion is flowing well and at a normal pace.
  • Fat absorption: If stool is yellow to yellow-brown, fat is not being absorbed from the stool as it moves through the colon. There will often be other symptoms, such as belly pain and discomfort. See your physician if you experience stool of this color.
  • Iron supplement use or internal bleeding: If your stool is very dark brown or black, this is likely a product of food or iron supplements. However, bleeding high up in the digestive tract is possible. See a physician as soon as you experience this characteristic.

Why is stool color important?

The color of stool matters because it shows what kinds of foods are being eaten, at least in the general sense. It also shows how long it takes food to travel through the intestinal tract. If food is digested too slowly or too quickly, this can cause chronic issues. Stool color can also give early warning of potentially severe conditions, such as bleeding in the digestive tract.

What Causes Dark Brown Stool or Diarrhea?

Dietary causes

Your diet can affect the color of your stool, such as the following.

  • Eating more red meat: This might cause darker brown stools due to the iron content of meat.
  • Eating dark blue or black-colored foods: Blackberries, blueberries, or black licorice might cause the stool to look almost black due to the staining pigments of these foods.
  • A gluten intolerance may cause yellow to yellow-brown stools: This is due to interference with digesting fats.
  • Very dark stools after drinking alcohol: This may be due to the alcohol irritating stomach ulcers or intestinal lesions, causing them to bleed.

Medications and supplements

Medications and supplements that can impact stool color include:

  • Iron tablets: Or vitamins containing iron.
  • Anti-diarrhea medicines: These contain ingredients that can cause very dark stools.


Illnesses can result in varying stool colors.

  • Constipation: This causes stool to stay in the intestine longer and become drier. These things will make it appear darker.
  • Food allergies: The resultant bowel inflammation can cause rapid changes from diarrhea to constipation, often with dark stools.
  • Stomach ulcers: If they bleed, the digested blood can turn the stool very dark.
  • Tumors or other growths within the small or large intestine: If these bleed, the stool will appear brown-black to black.

Non specific stool change

There are many factors affecting the appearance of someone's stools. Often a variation in stool color and/or consistency is caused by food or medicines. Leafy greens and certain vegetables like spinach and kale can make stool look green. Iron supplements and medicines containing bismuth like Pepto-bismol can turn stools black. It looks like your stool change is probably a variation of normal.

Rarity: Common

Top Symptoms: black stool, green poop, dark brown stool, red stool

Symptoms that never occur with non specific stool change: tarry stool, weight loss, rectal bleeding, fever

Urgency: Wait and watch

Constipation resulting from dehydration

Constipation means difficulty in passing bowel movements. A common cause of constipation is dehydration, or insufficient water in the body. If the contents of the bowel are not kept full and lubricated by plenty of fluid, the waste can become dry and packed and very hard to pass.

Most susceptible are pregnant women, especially those with a condition called hyperemesis gravidarum. This syndrome causes severe nausea and vomiting throughout most of the pregnancy and can easily lead to dehydration.

Anyone with an illness that causes prolonged vomiting and diarrhea will soon become dehydrated. A number of prescription medications can act as diuretics, meaning they cause the body to lose extra fluid through the urine.

The use of alcohol, or illegal drugs such as cocaine, also has a very dehydrating effect. The ill effects called a "hangover" that often happen after a night of drinking are actually due to the dehydration caused by the alcohol.

Treatment involves rehydrating, either with plain water by mouth or, in severe cases, hospitalization for IV fluid rehydration.

Rarity: Common

Top Symptoms: constipation, constipation, general abdominal pain, pain in the lower left abdomen, pain when passing stools

Symptoms that always occur with constipation resulting from dehydration: constipation

Symptoms that never occur with constipation resulting from dehydration: vomiting

Urgency: Self-treatment

Normal variation of constipation

Constipation means bowel movements which have become infrequent and/or hardened and difficult to pass.

There is wide variation in what is thought "normal" when it comes to frequency of bowel movements. Anywhere from three times a day to three times a week is considered normal.

As long as stools are easy to pass, laxatives should not be used in an effort to force the body to a more frequent schedule.

Constipation is usually caused by lack of fiber in the diet; not drinking enough water; insufficient exercise; and often suppressing the urge to have a bowel movement.

A number of medications and remedies, especially narcotic pain relievers, can cause constipation.

Women are often affected, due to pregnancy and other hormonal changes. Young children who demand low-fiber or "junk food" diets are also susceptible.

Constipation is a condition, not a disease, and most of the time is easily corrected. If simple adjustments in diet, exercise, and bowel habits don't help, a doctor can be consulted to rule out a more serious cause.

Rarity: Common

Top Symptoms: abdominal pain (stomach ache), nausea, stomach bloating, constipation, constipation

Symptoms that always occur with normal variation of constipation: constipation

Symptoms that never occur with normal variation of constipation: vomiting

Urgency: Self-treatment

Chronic constipation

Constipation is a very common condition affecting the large intestine. It is characterized by difficulty passing stool, or passing stool less often. Commonly it is linked to not eating enough dietary fiber, not drinking enough fluids, or not getting enough exercise. Some medications can cause constipation as well.

Rarity: Common

Top Symptoms: stomach bloating, constipation, abdominal cramps (stomach cramps), pain when passing stools, rectal bleeding

Symptoms that always occur with chronic constipation: constipation

Symptoms that never occur with chronic constipation: unintentional weight loss

Urgency: Primary care doctor

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Treatments for Dark Brown Poop and Diarrhea

When to see a doctor

See a doctor if you experience the following. Depending on their findings, they will develop a treatment plan accordingly.

  • Dark brown stool that keeps turning darker: Especially if it actually looks tarry and black. Make an appointment as soon as possible.
  • Yellow or yellow-brown stool: If it does not clear up within a day or so.
  • Any color change that happens suddenly

At-home treatments

Try the following treatments at home to possibly relieve symptoms.

  • Eat a balanced diet: Eat a diet high in lean protein, vegetables, and fruits and relatively low in fats. The fats found in french fries, potato chips, and other highly processed foods are the most damaging.
  • Limit constipation: Drink plenty of water, eat a high-fiber diet, and do not delay a bowel movement when it's time to have one.

FAQs About Dark Brown Stool

Here are some frequently asked questions about dark brown stool.

When should you seek medical attention for dark brown stool?

Dark brown stool can be a sign of intestinal bleeding. However, other foods can cause dark stool as well as iron, iron supplements, or dark, leafy greens, such as spinach or kale. Seek medical attention if you have any signs of blood loss or believe that your risk of gastrointestinal bleeding is higher. If you have gastric ulcers, cirrhosis, diverticulitis (outpouchings of the intestines), or have undergone chemotherapy, see a physician immediately. If you have any signs of anemia — weakness, fatigue, shortness of breath, dizziness, decreased exercise tolerance, or pale skin — you should also see a physician immediately.

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

Exposure to bile over a longer period can cause darker stool. If your bowel movements are infrequent, and you are consuming large amounts of fatty food, this can also occur. Bile can color stool a dark brown or dark green color, which can become more saturated if your stool stays in the intestine longer. Generally, this color change will resolve as your bowels begin to move again.

Do certain medications cause dark brown stool?

Yes, certain medications can cause dark brown stool. Iron and bismuth (in over-the-counter drugs like Pepto Bismol) commonly cause dark stools. Additionally, licorice, blueberries, or any food with a dark red, purple, blue, or green dye can cause darker stools. Beets, tomatoes, and food colorings can cause red-colored stool.

Why do I have dark brown stool with no pain?

Dark brown stool can be perfectly normal. Unless you are experiencing signs of blood loss, like blood in the toilet bowl or on your feces, or dizziness, weakness, fatigue, shortness of breath, decreased exercise tolerance, or pale skin, it is likely that dark brown stool is a product of the foods you consumed or the beverages you consumed.

Why do I have dark brown stool before my period?

Dark brown stools prior to menstruation may be due to constipation from a change in hormones. As your menstrual cycle begins, your body may hold onto water, and this can cause your bowel movements to move more slowly. Your stool may spend a longer amount of time in your intestine, especially if your body is secreting bile to digest fats and other animal products.

Questions Your Doctor May Ask About Dark Brown Stool

  • Have you experienced any nausea?
  • Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
  • Any fever today or during the last week?
  • Have you had any changes in your weight?

Self-diagnose with our free if you answer yes on any of these questions.

Hear what 1 others are saying
Chocolate Syrup StoolPosted November 30, 2019 by J.

Male age 92. I have a chocolate syrup colored and consistency stool persistence for greater than 24 hours. No stomach pain, however cannot eat very much at a time. Has no nerves to the esophagus for over 15 years and get Botox injections with dilation of the muscle at the end of the esophagus every 2 months.

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