Understanding Melena: Symptoms, Causes, and Differences from Hematochezia

Melena is a term commonly associated with black, tarry stools that are a sign of gastrointestinal bleeding. This condition typically originates from the upper gastrointestinal (GI) tract, which includes the mouth, esophagus, stomach, and the first part of the small intestine. In some cases, bleeding from the ascending colon in the lower GI tract can also result in melena. Understanding melena is essential for proper diagnosis and treatment, and it is crucial not to confuse it with hematochezia, which refers to fresh blood in the stools and typically originates from the lower GI tract.

What is Melena?

Melena is characterized by the production of black, tarry stools. This discoloration is due to the breakdown of blood in the stomach and intestines, which results in the formation of ferrous sulfide. The symptoms of melena may include:

Black, tarry stools Nausea Abdominal pain Vomiting Weakness or dizziness

Causes of Melena

The primary causes of melena are gastrointestinal bleeding, which can be caused by various factors. Some common causes include:

Gastroesophageal Reflux Disease (GERD): Damage to the esophageal lining can lead to bleeding. Hemorrhoids: Although associated with hematochezia, internal hemorrhoids can also sometimes cause melena. Peptic Ulcers: Ulcers in the stomach or duodenum can bleed and cause melena. Gastrointestinal Infections: Bacterial or viral infections can lead to inflammation and bleeding. Medications: Certain medications such as NSAIDs, aspirin, and anti-inflammatory drugs can irritate the GI tract and cause bleeding. Gastrointestinal Tumors: Benign or malignant tumors can lead to internal bleeding.

Differences between Melena and Hematochezia

To better understand melena, it is essential to differentiate it from hematochezia, another condition involving the presence of blood in the stools. While both conditions involve bleeding, they are characterized by different symptom presentations and origins:

Time of Appearance: Melena involves black, tarry stools due to the breakdown of blood, which takes time to travel through the digestive system. Hematochezia, on the other hand, involves bright red or maroon-colored stools due to recently bleeding blood. Location of Bleeding: As mentioned earlier, melena typically originates from the upper GI tract. Hematochezia, on the other hand, is usually caused by bleeding in the lower GI tract, such as the rectum or colon. Detection: Melena can be detected through the color of the stool, while hematochezia is more easily identified due to the bright color of the blood.

Conclusion

Understanding melena is crucial for recognizing the signs of gastrointestinal bleeding and seeking appropriate treatment. It is important to differentiate melena from hematochezia, as they have distinct symptoms, causes, and treatments. If you experience black, tarry stools or any other gastrointestinal symptoms, it is advisable to consult a healthcare professional for accurate diagnosis and personalized care.

Keywords: melena, gastrointestinal bleeding, hematochezia