Why Is My Poop Black? Causes, What It Means, and When to Get Treatment

You might not know that poop color and consistency can offer clues about the health of your diet and digestive system. So it’s important to pay attention to any changes. 

Sometimes, a change in poop color can point to a serious underlying problem, like stomach or intestinal bleeding — and even cancer. Here, we’ll outline some common reasons for black poop, including when you should see a healthcare professional.

What color of poop is normal and healthy?

Any shade of brown is normal for poop. Even a greenish tinge can be normal for some people on some days. You’re the best expert on what’s normal for you. 

It’s very normal for the color of your poop to change depending on what you eat or the medications you’re taking. 

The amount of bile in the stool also affects the color. Bile is a yellow-green digestive fluid made by the liver and stored in the gallbladder. It’s released into the gastrointestinal (GI) tract when you eat to help digest food. It mixes with food waste to produce the classic brownish-green, healthy poop color.

What are some causes of black poop?

There are many things that can change the color of your poop, some more serious than others. Certain foods, medications, and serious medical conditions can all cause black poop.

Bleeding in the GI tract

One of the most serious causes of black poop is bleeding in the GI tract. This type of black poop is known as melena. It can often be very sticky with a foul-smelling odor, and it can also be referred to as “tarry” or tar-like stool. 

Melena can be the result of bleeding in the upper part of the GI tract from conditions like: 

• Peptic ulcer: This is a sore in the lining of your stomach or upper intestines. Peptic ulcers often cause a burning, painful sensation in your stomach.

• Varices: When veins in the esophagus — the tube carrying food from the mouth to the stomach — become enlarged, they can rupture and bleed. This often happens if you have liver problems, like cirrhosis.

• Esophagitis: This is inflammation and swelling in the esophagus lining. You might feel pain from swallowing. It’s typically due to too much acid within the esophagus and stomach.

• Gastritis: This is inflammation of the stomach lining. You might have stomach pain, nausea, and vomiting. It’s also caused by too much acid production in the stomach.

• Arteriovenous malformation (AVM): An abnormal grouping of blood vessels, AVMs can weaken and rupture easily, causing bleeding. This can occur anywhere in the GI tract.

• Mallory-Weiss tear: The tissue of your esophagus can tear, especially after periods of forceful coughing or vomiting. This can also cause stomach pain and vomiting blood. 

EXPERT PICKS: WHAT TO READ NEXT

• What if your poop is green, not black? Learn more about the foods, medications, and medical conditions that can turn your poop green. 

• Understanding the shape of your poop: The Bristol Stool Chart can help you track your bowel habits and what they mean for your digestive health.

• A bleeding peptic ulcer is a common cause of black poop. Treatment with medication decreases stomach acid and helps the ulcer heal.

GI cancers

Cancer can happen in different parts of your GI tract. In some cases, black poop might be a sign of bleeding from a type of cancer, such as:

• Gastric cancer: This cancer grows in the stomach. Other signs of stomach cancer can include nausea, abdominal pain, vomiting, always feeling full (early satiety), and weight loss. 

• Esophageal cancer: This cancer affects the esophagus. You might also have problems with swallowing, eating, weight loss, a hoarse voice, or cough that won’t go away. 

• Colorectal cancer: This cancer is from tumors in the colon and rectum. It doesn’t cause symptoms in early stages. But it can cause changes in bowel habits, shape, and color, including black and/or bloody stools.

Medications that can cause black poop

There are a few medications that cause your poop to turn black. This is usually harmless and temporary. But it can last for a few days after taking the medicine. The most well-known include:

• Iron supplements

• Activated charcoal 

• Stomach-upset medicines that contain bismuth salicylate (like Kaopectate and Pepto- Bismol)

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Foods that can cause black poop

Naturally occurring dark-colored foods or foods with dark food coloring can cause the color of your poop to change. 

The foods that most often cause your poop to turn black include:

• Black licorice

• Blueberries

• Blood sausage

When should you see a healthcare professional about black poop?

Fortunately, a medical problem isn’t always the reason for black poop. But it’s potentially serious. So you should get medical attention first, before assuming it’s due to something you ate. 

A few signs that can signal your black poop could be something more serious: 

• Black poop that won’t go away

• Changes in poop shape or consistency

• Changes in bowel habits

• Feeling dizzy or lightheaded

• Abdominal pain

• Indigestion or heartburn

• Nausea and/or loss of appetite

• Vomiting blood or material with a coffee-ground texture

If you experience any of these, it’s best to notify your healthcare team sooner versus later.

Are there any black stool treatments?

There isn’t a treatment for black poop, per se. Rather, treatment will be based on what caused your stool to have a change in color. Your medical team will have to take a close look at your medical history and run some tests to figure out why you’ve developed black stools.

If you have black stool from medication or food, it should return to normal once you stop taking or eating it. If your stools are black due to bleeding from an ulcer or inflammation, you’ll likely take medication to treat those conditions. Black stool treatments for bleeding due to blood vessel problems or cancers may require procedures or surgery to treat.

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Written by:

Windy Watt, DNP, APRN, FNP-BC

Windy Watt, DNP, APRN, FNP-BC, is a board-certified family nurse practitioner with 30 years of experience. She has an extensive background in critical care, internal medicine, family practice, and urgent care.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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