Causes Of Black Stool In Adults And When To Worry

Black poop is caused by two main reasons. It could be something that you just ate or it could be something more complicated than that. There are several medical reasons why your stool is black and almost tarry. If you have abdominal pain, diarrhea, or a fever with black stool, please visit a doctor immediately.

black poop

The color and smell of your poop can relieve a lot about your health and diet. Any shade of brown is considered normal and healthy. But, here’s the truth, there are different shades of poop. Ranging from the hues of brown to yellow, white, and even green.

Black poop can be caused by two main reasons. One, it could be something you ate or drank. Or, the second reason is when blood gets mixed into your poop.

Dietary Causes Of Black Stool In Adults

You might be surprised to know, but the color of your poop has a lot to do with what you just ate and the amount of bile involved. Bile is a greenish fluid released by the liver to help break down fat for digestion.

If the color of your food is too dark or if you are on certain medications, the chances to see black poop are high. Here are a few possibilities:

  • Black licorice
  • Blueberries
  • Dark chocolate cookies
  • Fruit punch
  • Blood sausages
  • Prunes
  • Certain veggies like beets and cranberries

You could also experience black stool if you take iron supplements. Because the medicine is high in iron and this leads to a much darker shade of stool. This is the reason why pregnant women (who are given iron tablets and other prenatal vitamins) and anemic people (given iron supplements) might have black poop. Also, newborns can have black poop initially, because of swallowing traces of their mother’s blood during labor.

Another reason to get black stool is if you frequently consume certain kinds of medication such as anticoagulants or nonsteroidal anti-inflammatory drugs (NSAID).1

Medical Causes Of Black Stool In Adults

Medical Causes Of Black Poop

Sometimes the reason for black poop can indicate a serious problem. If the poop looks black and almost like tar, it could be a sign of a bleeding in the upper gastrointestinal tract. When blood gets mixed in the stool, it becomes very dark in appearance. The condition is known as melena and it is considered a medical emergency.

This could happen if you have one of the below conditions.

1. Peptic Ulcers

Peptic ulcers are a very common problem. These are ulcers that usually develops in the inner lining of your stomach or the small intestine. It could be caused by bacteria, excessive alcohol, smoking, or taking certain medication frequently. One study found out melena is mainly caused by a peptic ulcer.2

2. Esophageal Varices

Tar-like black stool could be a symptom of esophageal varices. When blood flow to the liver gets blocked, swollen veins in the lower esophagus (close to your stomach) get damaged and bleed out.

3. Cancer

Certain types of cancer can lead to a black stool. Colon cancer occurs when cancerous cells start growing from the colon or rectum and spread to other nearby organs. Black stool can also be a symptom of stomach cancer. In this type, healthy cells turn cancerous over a period of years in the inner lining of the stomach.

4. Tumors

Sometimes malignant tumors could cause black stool. This type of tumor usually targets the esophagus and stomach and this could lead to black stool.

5. Gastritis

Gastritis is a condition when the stomach lining becomes inflamed. The inflammation could last for years if not treated causing a lot of pain and discomfort. Black stool is a common symptom of erosive gastritis – a type of gastritis with little inflammation and formation of ulcers in the stomach lining.

Do You Have These Symptoms As Well?

If you haven’t eaten anything that causes suspicion, check if you have the following symptoms along with black stool.

  • Abdominal pain
  • Nausea
  • Diarrhea
  • Fever
  • Rectal pain
  • Weight loss

Once you rule out dietary causes, go to a doctor immediately. Black stool caused by a medical reason can get serious if not treated.


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