Melena is when blood causes stools to appear black, tarry, and foul-smelling.
Melena is not a disease itself but rather a symptom of a condition that’s causing the bleeding.
Kevin Brine / Getty Images
What Causes Melena?
Kevin Brine / Getty Images
Stools maylook black and appear tarrybecause they contain blood.
The blood is dark because it is coming from somewhere in the upper digestive tract.
This means that there is a medical condition present that is causing bleeding.
The black stools could continue for even a few days after the bleeding stops.
It’s a common myth that stress causes these ulcers.
Some people with an ulcer have no symptoms.
But when there are symptoms, they can include gnawing or burning pain in the upper chest.
They are most commonly related to severe scarring in the liver, calledcirrhosis.
Varices may have no symptoms except bleeding.
The blood loss can be sudden and severe (acute).
More commonly, however, the bleeding is chronic (long-lasting).
It can be due to forceful vomiting.
It can be associated with vomiting from any cause but is sometimes associated with alcohol use disorder.
Erosive Esophagitis
Irritation or inflammation in theesophaguscould lead to bleeding in some cases.
Vascular Gastrointestinal Lesions
Vascular gastrointestinal lesions are rare.
They are abnormalities in blood vessels that may cause bleeding.
The cecum andascending colonare common places where these lesions might occur.
Tumors
Gastrointestinal stromal tumorsmay also cause bleeding that leads to melena.
They are very rare and are sparked by a mutation in certain genes.
These tumors occur most often in people between 50 and 60 years old.
What Else Could Cause Black Stool?
Black stool could also be resulting from something other than blood.
Most commonly, this includes foods that are dark blue or black.
This discoloration is usually harmless and will go away after the food is digested.
Black stools could also be caused byiron supplementsor bismuth subsalicylate (the active ingredient inPepto-Bismol).
As the dark color is not due to blood, it is not considered melena.
What Does Melena Look Like?
True melena that’s resulting from blood in the stool has certain characteristics.
Stool has a wide range ofnormal colors, but medium brown is typical.
Melena causes stool to be much darker, appearing black or nearly black.
Melenic stool is alsodifferent in texturefrom normal stools.
It is often described as tarry, meaning it is sticky and dense.
The third part of melena is the smell.
Other Symptoms With Melena
There may not be any other symptoms when melena starts.
When there are symptoms, they will vary based on the condition that is causing it.
There could also be vomiting or diarrhea, depending on the reason for the melena.
Significant blood loss could also be accompanied by dizziness, light-headedness, or even fainting.
How Do I Know If My Black Stool Is Melena?
When a black stool is melena, it will look tarry and smell offensive.
Having other symptoms in the digestive tract may also signal blood in the stool.
If there is a true concern that blood is in the stool, contact a healthcare provider.
A stool test called a fecal occult blood test might be used to detect the presence of blood.
Melena is a symptom of a problem, so there will be a need to determine the cause.
The treatment for melena is based on what is causing the bleeding.
Ulcers in the stomach or duodenum that are resulting from an infection withH.
pyloriwill be treated with acid-reducing medication and antibiotics.
Less common causes of bleeding may require treatments that include surgery and medications to help manage ulcers and inflammation.
Blood in the stool is never normal and is always a sign to see a healthcare provider.
Summary
Blood in the stool needs to be investigated by a healthcare provider.
Bleeding higher up in the digestive tract can result from several different conditions.
It’s important to receive a diagnosis so that treatment can begin.
Ansari P.Overview of gastrointestinal bleeding.
Vakil N.Peptic ulcer disease.
2017;23:3011-3016. doi:10.3748/wjg.v23.i17.3011
Ansari P.Vascular gastrointestinal lesions.
2019;25:2720-2733. doi:10.3748/wjg.v25.i22.2720
Villano A.Gastrointestinal stromal tumors (GISTs).
Gupta A, Shetty S, Mutalik S, et al.Treatment ofH.
pyloriinfection and gastric ulcer: need for novel pharmaceutical formulation.Heliyon.
2023;9(10):e20406.
doi:10.1016/j.heliyon.2023.e20406
MedlinePlus.Black or tarry stools.
