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Published on: 2/6/2026

Melena vs. Normal Stool: Why Your Poop is Black and Sticky

Black, sticky, tar-like stool usually means melena caused by digested blood from the upper digestive tract and needs prompt medical attention, while black stool that is not sticky and lacks a strong odor is often from iron, bismuth, charcoal, or dark foods and is usually harmless. Because causes, warning symptoms like dizziness or fatigue, medications such as NSAIDs or blood thinners, and a history of ulcers or liver disease can change what to do next, there are several factors to consider. See below for specific red flags, how doctors evaluate black stool, and the most appropriate next steps for your care.

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Explanation

Melena vs. Normal Stool: Why Your Poop Is Black and Sticky

Seeing a black and sticky stool can be surprising—and understandably concerning. While changes in bowel movements are common and often harmless, a specific type of stool known as "Black and Tarry" (Melena) deserves careful attention. This article explains the difference between melena and normal stool, what causes black and tarry poop, when it's serious, and what steps to take next—using clear, everyday language and medically credible information.


What Is Normal Stool Supposed to Look Like?

Normal stool can vary from person to person, but it usually falls within a predictable range:

  • Color: Medium to dark brown
  • Texture: Soft, formed, and easy to pass
  • Consistency: Similar to toothpaste or a smooth log
  • Odor: Unpleasant, but not unusually strong

The brown color comes from bile, a digestive fluid made by the liver. Changes in diet, hydration, or routine can temporarily alter stool color or shape without signaling a health problem.


What Does "Black and Tarry" (Melena) Mean?

Melena refers to stool that is:

  • Jet black or very dark
  • Sticky or tar-like in texture
  • Often shiny
  • Strong-smelling compared to usual stool

This specific combination matters. "Black and Tarry" (Melena) is not just darker stool—it usually means digested blood is present.

Why Does Blood Turn Stool Black?

When bleeding happens in the upper digestive tract—such as the esophagus, stomach, or first part of the small intestine—the blood is exposed to stomach acid and digestive enzymes. This process darkens the blood, turning it black and giving stool that tarry, sticky appearance.


Melena vs. Other Causes of Black Stool

Not all black stool is melena. Some everyday substances can darken stool without involving bleeding.

Common Non-Bleeding Causes of Black Stool

  • Iron supplements
  • Bismuth-containing medications (like certain stomach remedies)
  • Activated charcoal
  • Dark foods (such as black licorice or blueberries, in large amounts)

These causes usually:

  • Do not make stool sticky or tar-like
  • Do not cause a strong, foul odor
  • Resolve once the substance is stopped

Key Difference to Remember

  • Black stool without stickiness or odor → Often harmless
  • Black and Tarry (Melena) → More likely linked to bleeding and should be checked

What Causes Melena?

Melena typically points to bleeding higher up in the digestive system. Some causes are more common than others.

Possible Causes of Black and Tarry (Melena)

  • Stomach or duodenal ulcers
    Often related to H. pylori infection or long-term use of pain relievers like NSAIDs.
  • Gastritis
    Inflammation of the stomach lining.
  • Esophageal or stomach varices
    Enlarged veins that can bleed, often linked to liver disease.
  • Tears in the esophagus
    Can occur after severe vomiting.
  • Upper GI tumors
    Less common, but important to rule out.

Not all causes are life-threatening, but many do require medical care.


Symptoms That May Appear Alongside Melena

Black and tarry stool may happen on its own, or with other symptoms such as:

  • Fatigue or weakness
  • Lightheadedness or dizziness
  • Shortness of breath
  • Abdominal discomfort
  • Nausea or vomiting

These symptoms can suggest blood loss over time. Even slow bleeding can affect the body if left untreated.


When Should You Take Black and Tarry Stool Seriously?

It's reasonable to monitor minor changes in bowel habits. However, melena is different.

Seek medical advice promptly if:

  • Stool is black, sticky, and tar-like
  • The change lasts more than a day or two
  • You feel weak, dizzy, or unusually tired
  • You have a history of ulcers, liver disease, or digestive conditions
  • You take blood thinners or long-term pain relievers

If symptoms feel severe or sudden, this may require urgent medical evaluation.


How Doctors Evaluate Black and Tarry Stool

A healthcare provider may:

  • Ask about medications, supplements, and diet
  • Check vital signs and signs of anemia
  • Order blood tests
  • Recommend stool testing
  • Arrange imaging or endoscopy if needed

The goal is to find the source of bleeding and treat it appropriately.


What You Can Do Right Now

If you notice black and tarry stool and are unsure what it means, a good first step is to review your symptoms carefully.

A helpful way to assess what you're experiencing is to use a free blood in stool symptom checker that can guide you in understanding whether your symptoms require immediate care or a scheduled visit with your doctor.

This kind of tool does not replace a doctor—but it can help you prepare for a conversation with one.


Can Melena Go Away on Its Own?

If black stool is caused by food or supplements, it often resolves quickly once those are stopped.
True melena, however, usually does not resolve without addressing the underlying cause.

Ignoring ongoing black and tarry stool can allow bleeding to continue silently, which may lead to complications over time.


How Is Melena Treated?

Treatment depends on the cause but may include:

  • Medications to reduce stomach acid
  • Antibiotics for infections
  • Stopping or adjusting certain medications
  • Procedures to stop active bleeding
  • Treating underlying conditions like ulcers or liver disease

Many treatments are effective, especially when started early.


A Reassuring but Honest Takeaway

It's important not to panic—but it's also important not to ignore Black and Tarry (Melena). While some stool color changes are harmless, melena has a specific look and meaning that usually points to bleeding in the digestive tract.

Pay attention to:

  • Color
  • Texture
  • Smell
  • How long it lasts

And most importantly, speak to a doctor about any symptoms that could be serious or life-threatening. Early evaluation can make a real difference and often leads to straightforward treatment.

If something feels off, trust that instinct and get medical advice. Your digestive health is an important part of your overall well-being.

(References)

  • * Laine L, Barkun AN, Saltzman JR, Correia L, Leontiadis GI. ACG Clinical Guideline: Upper Gastrointestinal Bleeding. Am J Gastroenterol. 2021 May 1;116(5):899-922. doi: 10.14309/ajg.0000000000001245. PMID: 33855909.

  • * Hocker AM, Harrison K. Differential diagnosis of black stools. Nurse Pract. 2018 Jan;43(1):16-21. doi: 10.1097/01.NPR.0000527339.42171.4b. PMID: 29215440.

  • * Marmo R, Miele L, Di Sabatino A, Manes G, Rotondano G. Acute upper gastrointestinal bleeding: a medical emergency. Eur Rev Med Pharmacol Sci. 2023 Apr;27(7):2934-2947. doi: 10.26355/eurrev_202304_31968. PMID: 37052309.

  • * Gralnek IM, Panel P. Acute Upper Gastrointestinal Bleeding: Initial Evaluation and Management. Clin Gastroenterol Hepatol. 2023 Feb;21(2):302-311. doi: 10.1016/j.cgh.2022.09.027. Epub 2022 Oct 1. PMID: 36195287.

  • * Khasawneh A, Akbari M, Sharma S. False Melena: A Diagnostic Pitfall. Cureus. 2023 Mar 22;15(3):e36502. doi: 10.7759/cureus.36502. PMID: 37090288; PMCID: PMC10121115.

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