Black and Tarry Stool: Causes, Symptoms, and When It’s an Emergency

Black and Tarry Stool (Melena): Causes, Symptoms, and When It's an Emergency

Seeing black and tarry stool (melena) can be alarming. While there are harmless reasons for dark-colored stools, true melena often points to bleeding somewhere in the upper digestive tract and deserves careful attention. This guide explains what black and tarry stool is, what causes it, symptoms to watch for, and when to seek urgent medical care—using clear, everyday language without unnecessary alarm.

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What Is Black and Tarry Stool (Melena)?

Black and tarry stool, medically called melena, is stool that appears jet black, shiny, and sticky, often with a strong, unpleasant odor. The color and texture happen when blood is exposed to stomach acid and digestive enzymes as it travels through the gastrointestinal (GI) tract.

Melena usually means bleeding from the upper GI tract, which includes the:

• Esophagus
• Stomach
• First part of the small intestine (duodenum)

Because digestion changes the blood, melena looks different from bright red blood in stool, which typically comes from the lower GI tract.

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Why Stool Turns Black and Tarry

The black color comes from hemoglobin in blood breaking down during digestion. This process takes time, which is why melena often signals bleeding higher up in the digestive system.

However, not all black stool is melena. Some foods and medications can darken stool without bleeding (more on that below).

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Common Causes of Black and Tarry Stool (Melena)

Melena can have several causes, ranging from treatable to serious. The most common include:

1. Peptic Ulcers

• Open sores in the stomach or duodenum
• Often linked to H. pylori infection or long-term use of NSAIDs (like ibuprofen or aspirin)
• A leading cause of upper GI bleeding

2. Gastritis or Esophagitis

• Inflammation of the stomach lining or esophagus
• Can result from alcohol, smoking, medications, or acid reflux
• May cause slow, ongoing bleeding

3. Esophageal or Gastric Varices

• Enlarged veins in the esophagus or stomach
• Often associated with chronic liver disease
• Can bleed suddenly and heavily

4. Mallory–Weiss Tears

• Small tears in the lining of the esophagus
• Usually caused by severe vomiting or retching
• Bleeding may be short-lived but noticeable

5. Stomach or Esophageal Cancer

• Less common, but important to rule out
• May cause slow bleeding over time, leading to melena and anemia

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Non-Bleeding Causes of Black Stool (Not Melena)

Sometimes stool looks black but isn't tarry or sticky and doesn't involve bleeding. Common non-bleeding causes include:

• Iron supplements
• Bismuth-containing medications (such as certain stomach remedies)
• Dark foods (black licorice, blueberries, blood sausage)

If stool is black without a tar-like texture or strong odor—and you feel otherwise well—these causes are more likely. Still, it's worth mentioning to a healthcare professional.

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Symptoms That May Occur with Melena

Melena can appear alone or with other symptoms. Pay attention to how you feel overall.

Possible accompanying symptoms:

• Abdominal pain or discomfort
• Nausea or vomiting
• Fatigue or weakness
• Dizziness or lightheadedness
• Shortness of breath
• Pale skin (a sign of anemia)

More serious warning signs:

• Vomiting blood (which may look red or like coffee grounds)
• Fainting or near-fainting
• Rapid heartbeat
• Confusion or difficulty staying alert

These symptoms suggest significant blood loss and require urgent medical care.

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When Is Black and Tarry Stool an Emergency?

Black and tarry stool can be a medical emergency, especially if it happens suddenly or is accompanied by other symptoms.

Seek immediate medical care if you have:

• Black, tarry stool plus dizziness, weakness, or fainting
• Black stool along with vomiting blood
• A history of liver disease, ulcers, or GI bleeding
• Ongoing black stools lasting more than a day or two
• Signs of anemia (fatigue, shortness of breath, pale skin)

If you're unsure, it's safer to be evaluated promptly. Upper GI bleeding can worsen quickly without treatment.

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How Doctors Evaluate Black and Tarry Stool

A healthcare professional will focus on identifying whether bleeding is present and where it's coming from.

Common steps include:

• Medical history and medication review (NSAIDs, blood thinners, supplements)
• Physical exam
• Blood tests to check for anemia or infection
• Stool testing for blood
• Upper endoscopy (a camera to view the esophagus and stomach)

These tests help guide treatment and rule out serious causes.

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Treatment Options for Melena

Treatment depends on the underlying cause and severity of bleeding.

Possible treatments:

• Medications to reduce stomach acid and allow healing
• Antibiotics if H. pylori infection is present
• Endoscopic procedures to stop active bleeding
• IV fluids or blood transfusions for significant blood loss
• Surgery in rare, severe cases

Early evaluation often leads to simpler, more effective treatment.

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What You Can Do Right Now

If you notice black and tarry stool, take a moment to assess:

• Your recent foods and medications
• Whether the stool is sticky and foul-smelling
• Any additional symptoms like weakness or pain

If you're unsure what's causing your symptoms or how urgently you need care, you can use a free AI-powered symptom checker for black or tarry stool to help you understand what might be happening and whether you should see a doctor right away.

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When to Speak to a Doctor

You should speak to a doctor if:

• You have black and tarry stool even once and don't know the cause
• The stool color persists or keeps returning
• You have risk factors such as ulcers, liver disease, or long-term NSAID use
• You feel unwell, tired, dizzy, or short of breath

If anything feels life-threatening or rapidly worsening, seek emergency medical care immediately.

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A Reassuring but Honest Final Word

Black and tarry stool (melena) doesn't always mean a medical crisis—but it should never be ignored. Many causes are treatable, especially when caught early. Paying attention to your body, avoiding assumptions, and getting timely medical advice can make a real difference.

If you're uncertain, start by checking your symptoms, then speak to a doctor who can guide you safely and appropriately. Your health—and peace of mind—are worth it.