Illustration by Michela Buttignol for Verywell Health
What Is Black Poop?
But it can also be a sign of melena, which means there’s blood in your stool.
With melena, the blood turns black as it moves through the body.
Illustration by Michela Buttignol for Verywell Health
Digestive enzymes break it down in the digestive tract, changing its color and texture to black.
Iron supplements, Pepto-Bismol, and certain dark foods can cause black stool, but this isnt true melena.
Because it undergoes minimal digestion, it remains red rather than turning black.
If theres any doubt, it’s best to see a healthcare provider right away.
What Causes Melena?
One instance of black stool isnt always a cause for panic.
However, if it happens repeatedly or comes with symptoms like stomach pain ordizziness, it could be melena.
In that case, the cause may be serious and even life-threatening.
This bleeding can result in melena.
Another possible outcome of chronic gastritis is the development ofpeptic ulcers, which are sores in the stomach lining.
If the bleeding is rapid or severe, it may cause vomiting blood or bright red stools instead.
Esophageal Varices
Esophageal varicesare enlarged veins in the wall of the lower esophagus or upper stomach.
Bleeding esophageal varices require immediate medical care to stop the bleeding, as they can lead to sudden death.
If it bleeds, it can cause melena.
Most cases result from forcefulvomiting, coughing, or straining.
Mallory-Weiss tears account for about 5% to 15% of gastrointestinal bleeding cases.
Like other conditions that cause melena, symptoms of a Mallory-Weiss tear may not be obvious.
When symptoms due occur, they may resemble the symptoms of internal bleeding.
Liver Disease
Liver diseasecan damage the veins that move blood into the liver.
This can cause pressure to build up in the veins, eventually causing them to burst.
When this happens, you may vomit blood or have black, tarry stool.
This bleeding can be life-threatening, so you should see an emergency medical provider right away.
These viruses affect the body’s blood vessels, making them more prone to leakage and causing internal bleeding.
When this bleeding occurs in the digestive tract, it can result in melena.
Types of viral hemorrhagic fevers include:
Viral hemorrhagic fevers are rare in developed countries.
Other Causes of Black Poop
Not all black stools are true melena.
If it doesn’t, or if the stool looks black and tarry, contact your healthcare provider.
If you think a medication or supplement is turning your poop black, call your healthcare provider.
They can confirm if it’s a normal side effect or if you need an evaluation.
Can Dehydration Cause Black Poop?
Dehydrationalone usually doesnt cause black stools.
If your stool appears black and tarry or youre unsure, contact your healthcare provider for advice.
They might do a stool test to check for hidden blood.
If the bleeding is lower in your digestive system, they might use acolonoscopyinstead.
Blood tests can also check foranemia, which happens when you’ve lost too much blood.
If a medication is to blame, the discoloration will stop once you discontinue it.
Since black stool can indicate internal bleeding, your provider may recommend an immediate evaluation.
How Dark Is Too Dark for Poop?
Normal stool ranges from brown to greenish-brown, and dark brown is usually harmless.
If it persists for more than a few bowel movements, consult a healthcare provider.
Summary
Black stool isn’t always a sign of a bigger health problem.
Your poop may look black as a result of food you ate or iron supplements you took.
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