Causes of Melena

The main cause of true melena is due to digestive system bleeding, and the types of bleeding include:

  • Gastrointestinal bleeding
  • Esophageal bleeding
  • Stomach bleeding
  • Duodenal bleeding
  • Jejunal bleeding
  • Ileum bleeding
  • Ascending colon bleeding

Intestinal Disorders: Colon conditions can cause melena if they cause intestinal bleeding (although they are somewhat more likely to cause hematochezia than melena):

  • Colon cancer
  • Small bowel tumor
  • Mesenteric vascular occlusion
  • Ischemic bowel disease
  • Mesenteric ischemia (mesenteric thrombosis)

Esophagus Disorders: Esophageal conditions can cause melena if they cause esophageal bleeding with swallowed blood, but they may also cause vomiting blood (or sometimes both symptoms):

Gastric Disorders: Stomach conditions that cause stomach bleeding may cause melena (and often also hematemesis), such as:

Swallowed Blood: The swallowing of blood into the stomach, rather than bleeding within the stomach, can also sometimes cause melena (although often also hematemesis), such as:

  • Swallowed blood
  • Nosebleeds
  • Oral bleeding
  • Dental bleeding
  • Facial injury
  • Cheek fracture
  • Esophageal bleeding
  • Skull fracture (postnasal drip bleeding)

Infectious Diseases: Some infectious conditions severe enough to cause internal bleeding and melena include:

Other Causes: Other disease causes of melena include:

Substance Causes: Other possible substance-related causes of melena include:

Melena-like Disorders: Causes of stool symptoms similar to melena, but not actually melena (false melena), include:

  • Black food coloring (e.g. licorice)
  • Lead ingestion
  • Iron ingestion
  • Bismuth ingestion
  • Red wine
  • Charcoal ingestion
  • Some other substances

Similar Symptoms: See also the causes of various related and similar symptoms:

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.