Symptoms A-Z

Dark Brown Stool Symptoms, Causes & Common Questions

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.

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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 might also be called feces.

Common characteristics of stool

Normal stool is medium to dark brown, about the color of milk chocolate. This color is healthy because it indicates that:

  • You are likely eating a good diet: Normal amounts of the nutrients needed for the digestive tract to function properly are being consumed
  • If bilirubin levels are normal: 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 proceeding in a normal way and at a normal pace — not too quickly or too slowly.
  • 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. Stool of this color should be investigated by your medical provider.
  • If stool is very dark brown to black: You have been consuming foods or medications that can turn the stool very dark, such as iron supplements. There is internal bleeding high up in the digestive tract. This must be investigated by your medical provider as soon as possible.

What stool color indicates

Why does stool color matter? The color of stool matters because it shows several facts quite plainly:

  • What kinds of foods are being eaten: At least in the general sense
  • How long it took the food to travel through the intestinal tract: If it moves too slowly or too quickly, this can cause chronic and debilitating digestive problems
  • It can give early warning of potentially serious conditions: Such as bleeding in the digestive tract

What Causes Dark Brown Stool or Diarrhea?


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.

4 Possible Dark Brown Stool Conditions

The list below shows results from the use of our quiz by Buoy users who experienced dark brown stool. This list does not constitute medical advice and may not accurately represent what you have.

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

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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

Treatments for Dark Brown Poop and Diarrhea

When to see a doctor for dark brown stool

You should schedule an appointment for:

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

At-home treatments for dark brown stool

Dark brown stool remedies that you can try at home include the following.

  • Eat a balanced diet: Eat a diet that is 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.
  • Avoid 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 intestinal bleeding. However, other food items can cause dark stool as well such as iron, iron supplements, or dark leafy greens such as spinach or kale. You should seek medical attention if you have any signs of blood loss or have reasons to believe that you might be at higher risk of gastrointestinal bleeding. If for example, you have gastric ulcers, cirrhosis, diverticulitis (outpouchings of the intestines), or have undergone chemotherapy, you should seek evaluation. If you have any signs of anemia (weakness, fatigue, shortness of breath, dizzyness, decreased exercise tolerance, pale skin) you should also seek immediate medial evaluation.

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

Exposure to bile over a longer period of time 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 intense if your stool stays in the intestine for a longer period of time. Generally, this color change will abate 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) can commonly cause darkened stools. Additionally, licorice, blueberries, or any food with a dark red, purple, blue, or green dye can cause darker stools. Beets, tomatoes, and certain candy 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 bowl or on the feces (dizziness, weakness, fatigue, shortness of breath, decreased exercise tolerance, 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 the onset of menses may be a product of constipation in association with a change in hormones. As your menstrual cycle begins, your body may be holding onto water and this can cause your bowel movements to move more slowly. The longer your stool spends in your intestine, especially if your body is secreting bile to digest fats and other animal products, this may occur.

Questions Your Doctor May Ask About Dark Brown Stool

To diagnose this condition, your doctor would likely ask the following questions:

  • 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?

The above questions are also covered by our A.I. Health Assistant.

If you've answered yes to one or more of these questions

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Dark Brown Stool Symptom Checker Statistics

People who have experienced dark brown stool have also experienced:

  • 14% Abdominal Pain (Stomach Ache)
  • 10% Diarrhea
  • 5% Constipation

People who have experienced dark brown stool were most often matched with:

  • 50% Constipation Resulting From Dehydration
  • 50% Normal Variation Of Constipation

Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

Dark Brown Stool Symptom Checker

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Disclaimer: The article does not replace an evaluation by a physician. Information on this page is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes.