As a rule, all human beings must pass out waste products from the body. One way is through the passage of stool (also known as poop or excreta). Most people have reported different colours of stool. Depending on a number of factors, it could signify normal health or a pathological (that is a diseased) state.

Stools should have a normal brown colour. But what does it mean for somebody to have a black stool? In medical jargon, Black Stool is Melena… some professionals prefer Black Tarry Stool.

Scary right?… It should not be once you understand why this is so. So calm down and read on!!!

It will be best to start from the beginning… How do poop get its normal colour?

Normal stool appears brown because of the action of bacteria and digestive enzymes on a pigment called bile. Bile is produced in the liver, stored in the gall bladder and secreted on food to help in the digestion of fat. The bile secretion happens in the small intestine.

Even though the colour of bile is greenish, the action of the bacteria on the food-bile mixture is sufficient to turn the colour to brown.

In this article, we try to help you understand what black poop really means, teach you when to see a doctor and explain what treatment options are available.

Melena itself is not a disease but is an indicator of an underlying issue. In other words, black stool is a symptom, a red herring to a major pathology*


Sometimes, some people causally notice a gradual but chronic change in the colour of their poop to black and have kept this to themselves until they were rushed to the Emergency Room due to shortage of blood.

Black poop means there is a significant amount of blood in the stool, not in the form you would expect. Remember that the digestive tract starts from the mouth and ends in the anus. A leakage of blood, which is bright red, from any of the blood vessels in the digestive tract, closer to the mouth, would most likely appear in the stool as Black.

Example; If a blood vessel is leaking blood into the esophagus, the food and blood and churned together as it moves into the stomach and subsequently into the intestine. Digestive juices and enzymes get to also mix with this ‘bloody food’, hence gradually changing the bright red colour in the mixture to a dark shade of colour, as there is ample time for the digestive actions of the enzyme on blood and food.

More Facts;…

It is generally agreed in the medical community that Upper digestive tract bleeding is the main cause of Melena.

In simple terms the initially bright red blood turns black when hemoglobin (a constituent of blood) is exposed to certain acids, enzymes, and digestive juices. So, this black color tells us that the blood originated from an area where those acids and juices are present.

Bleeding from the Esophagus, Stomach or the Duodenum (first part of the small intestine) causes black stools, as this blood is digested first then moves to the large intestine where it mixes with poop, turning it dark.

On the contrary, bright red blood indicates bleeding in the lower colon or rectum and usually presents as hematochezia– the presence of bright red blood in stool.



We have explained in clear terms what black poop is; bleeding from the upper digestive tract being a major factor in this case.

The next thing is to let you know some of the common conditions that cause Black poop, because these conditions are usually worse than they present, especially if not detected on time.

Before we proceed to our list of causes, here are some quick facts about black poop;

Fast Facts: What You Need to Know About Black Stools
  • Most cases of black stools are from eating black foods or iron supplements.
  • The most common condition causing black stools is a bleeding ulcer.
  • Black stools caused by blood indicate a problem in the upper digestive tract.
  • Blood in the stool can be detected through a stool test.
  • Black stool along with pain, vomiting, or diarrhea is cause to see a doctor right away.
  • If blood in the stool is suspected, you should contact your doctor as soon as possible.

Here is a list of 20 conditions that cause black poop…

1). Bleeding Oesophageal Varies:

Bleeding esophageal varices occur when swollen veins (varices) in your lower esophagus rupture and bleed. It is a surgical emergency.

The esophagus is the muscular tube that connects your mouth to your stomach. The veins in your lower esophagus near the stomach can become swollen when blood flow to the liver is reduced. This may be due to scar tissue or a blood clot within the liver.

When liver blood flow is obstructed, blood builds up in other blood vessels nearby, including those in your lower esophagus. However, these veins are much smaller, and they’re incapable of carrying large amounts of blood. They dilate and swell as a result of the increased blood flow.

The swollen veins are known as esophageal varices.

Esophageal varices may leak blood and eventually rupture. This can lead to severe bleeding and life-threatening complications, including death.

2). Gastric (Stomach) Ulcer

Stomach ulcers, which are also known as gastric ulcers, are painful sores in the stomach lining. Stomach ulcers are a type of peptic ulcer disease. Peptic ulcers are any ulcers that affect both the stomach and small intestines.

These ulcers occur when the thick layer of mucus that protects your stomach from digestive juices is reduced. This allows the digestive acids to eat away at the tissues that line the stomach, causing an ulcer.

As an ulcer, it may be easily cured, but they can become severe without proper treatment.

3). Peptic Ulcer

Peptic ulcers are sores that develop in the lining of the stomach, lower esophagus, or small intestine. The ulcers are usually formed as a result of inflammation caused by the bacteria Helicobacter pylori, as well as from erosion from stomach acids. Peptic ulcers are a fairly common health problem.

There are three types of peptic ulcers:

  • gastric ulcers: ulcers that develop inside the stomach
  • esophageal ulcers: ulcers that develop inside the esophagus
  • duodenal ulcers: ulcers that develop in the upper section of the small intestines, called the duodenum

The erosion of the walls could bleed causing black poop as a symptom.

4). Transfusion Reaction

Transfusion reaction is a medical entity where antibodies in the recipient’s blood can attack the donor blood if the two are not compatible. If the recipient’s immune system attacks the red blood cells of the donor, it is called a hemolytic reaction. The facts surrounding blood transfusion and transfusion reactions have been extensively studied hence, there is a low mortality rate globally.

Blood is commonly transfused based on blood components, such as red blood cells, platelets, or plasma. Before a blood transfusion, after a medical provider draws your blood. The sample will be sent to a laboratory for typing and cross-matching. Typing is when the lab determines blood type. Cross-matching is testing to determine if your blood is compatible with a donor’s blood of the same type.

5). Necrotizing Enterocolitis:

Necrotizing enterocolitis (NEC) is a disease that develops when the tissue in the inner lining of the small or large intestine becomes damaged and begins to die. This causes the intestine to become inflamed. The condition usually affects only the inner lining of the intestine, but the entire thickness of the intestine may become impacted eventually.

In severe cases of NEC, a hole may form in the wall of the intestine. If this occurs, the bacteria normally found inside the intestine can leak into the abdomen and cause widespread infection. This is a medical emergency.

6). Stomach Cancer

he National Cancer Institute (NCI) estimates there’ll be approximately 28,000 new cases of stomach cancer in 2017. The NCI also estimates that stomach cancer is 1.7 percent of new cancer cases in the United States.

While stomach cancer is relatively rare compared to other types of cancer, one of the biggest dangers of this disease lies in its early diagnosis. Since stomach cancer usually doesn’t cause any early symptoms, it often goes undiagnosed until after it spreads to other parts of the body. This makes it more difficult to treat.

Black poop is a common symptom of this cancer.

7). Alcohol Related Liver Disease

Alcohol-related liver disease (ARLD) is caused by damage to the liver following years of excessive drinking. Years of alcohol abuse can cause the liver to become inflamed and swollen. This damage can also cause scarring known as cirrhosis. Cirrhosis is the final stage of liver disease.

Liver disease is just one of the consequences of excessive alcohol consumption.

Types of Alcohol Related Liver Disease:

  • Alcohol Fatty Liver Disease
  • Acute Alcohol Hepatitis
  • Alcoholic Cirrhosis

8). Gastritis

Gastritis is an inflammation of the protective lining of the stomach. Acute gastritis involves sudden, severe inflammation. Chronic gastritis is a long-term inflammation lasting for years without any treatment. The stomach lining gets eroded resulting in a gradual loss of blood in stool – Black tarry stool.

9). Enteritis

This is the inflammation of the lining of the small intestine.

10). Acquired Platelet Function Dysfunction and other Blood Dyscrasias 


Depending on its cause, melena or black poop could be accompanied by a host of other symptoms. Using peptic ulcer as an example, the effect of the corrosion caused by the stomach’s acid, dark stools can be accompanied by a burning abdominal pain, nausea or vomiting of blood (hematemesis), while in stomach cancer, dark stools will be accompanied by weight loss, abdominal pain or fatigue.

So, here are some symptoms that are related to the passage of black stools:

  • Abdominal Pain.
  • Tiredness
  • Heartburn.
  • Nausea & Vomiting
  • Hematemesis (Vomiting blood)
  • Bloating.
  • Appetite Changes.
  • Dizziness
  • Weight loss

When Should You Go To The Doctor?

As already stated Black Poop is a symptom. Some underlying pathology is the cause of the black stool.

So ‘Yes’, Black stool should not be treated with kids gloves, especially if their are other accompanying symptoms.

If the upper gastrointestinal bleeding remain active, that is the stool is still black, it is pertinent that you go to a hospital as soon as possible.

A physician should be consulted straight away when you notice dark stools, as supposedly small bleeds could turn into an emergency.

A visit to a physician is very necessary to ascertain if the bleeding is active, how severe it is and the cause of the bleeding. The doctor would also treat it and try to prevent a recurrence.

FALSE MELENA: False Melena is the passage of dark stools that are not related to bleeding. 
It is usually caused by medication, supplements, food or some minerals.

You are completely Okay if the black stool is as a result of the following:
  • Black licorice
  • Blueberries
  • Iron supplements
  • Bismuth (Pepto-bismol)
  • Lead
They are food substances that cause False Melena... Surprised?!!!

Black Stool Treatment and Hospital Care?

It is totally right to go to a hospital once you notice that your poop is now totally BLACK.

The treatment for black stools would depend on exactly its cause; if not there would be a recurrence of the black stool. So, a major factor for adequate treatment is the cause of the black stool.

Generally, a doctor would assess melena by asking series of personal and not-so-personal questions to try to understand what its root cause is. This is the time to tell the doctor all you have noticed and how you are feeling. Seeing black stools in the toilet can be creepy and scary, but this is not the time to be scared. Tell the doctor all the details. Questions like when it started, if there are other accompanying symptoms and if there has been a diagnosis of peptic ulcer in the past etc, may be asked by the doctor.

The doctor will also carry out a physical examination to assess blood levels and will examine the abdomen. The doctor may perform a digital rectal exam (gently inserting a lubricated gloved finger into the anus) to look for signs of the black stool or to check if there is fresh blood.


Tests relevant for a proper diagnosis includes;

  • Blood tests
  • Stool microscopy
  • Esophagogastroduodenoscopy (EGD): A test that uses an electronically controlled camera device to examine the upper digestive tract.

Actual treatment of the causes of black stool may be medically based or surgically done.

Notoriously, the most common cause of melena is peptic ulcer.

Medical treatment involves using antibiotics and drugs that decrease acid secretion.

Surgical intervention would be employed when there is a severe cases of peptic ulceration, upper gastrointestinal tract cancers. Blood transfusion is needed in the event of massive blood loss.

Hospital admissions may be advised after the doctor assessment, especially if there is a huge amount of blood lost.

Note also that sometimes, there may  be no actual treatment if the Melena is False. The doctor would advise you accordingly on ways to identify and prevent false melena.


Black stool is a symptom that only an observant person will notice. Good timely intervention and treatment is assured when symptoms are reported on time.  So, every one is encouraged to maintain a strict health seeking behavior.



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