black stool

Black stool usually means that the blood is coming from the upper part of the gastrointestinal tract. The blood might be coming from the esophagus, stomach, and the first part of the small intestine. Blood will typically look like tar after it has been exposed to the body’s digestive juices. Stomach ulcers caused by ibuprofen, naproxen, or aspirin are common causes of upper GI bleeding.

Melena is a term used to describe black, tarry, and foul-smelling stools.

Why is my poop black?

Black poop is often caused by:

  • Bleeding stomach or duodenal ulcer
  • Gastritis
  • Mallory-Weiss tear (a tear in the esophagus from violent vomiting)
  • Trauma or foreign body
  • Bowel ischemia (a lack of proper blood flow to the intestines)
  • Vascular malformation

Other causes of black stool include:

  • Consuming black licorice
  • Consuming lead
  • Consuming iron pills
  • Medicines (Pepto-Bismol)
  • Eating too many blueberries

What to do when you have black stool

Talk to your doctor. Your doctor will want to know the exact color to help find the site of bleeding. Your doctor will probably perform an endoscopy or special x-ray studies.

Information for your doctor

When you visit your doctor, they will take a medical history and perform a physical examination, focusing on your abdomen and rectum.

Your doctor will ask you some of the following questions. This will be included in the ‘history’ to better understand the possible causes of your bloody or dark stools:

  • Is there blood on the toilet paper only?
  • What color is the stool?
  • When did it develop?
  • Have you had more than one episode of blood in your stool? Is every stool this way?
  • Are you taking blood thinners or NSAIDs (ibuprofen, naproxen, aspirin)?
  • Have you ingested black licorice, lead, Pepto-Bismol, or blueberries?
  • Have you had any abdominal trauma or swallowed a foreign object accidentally?
  • Have you lost any weight recently?

Questions to ask your doctor

  • What are symptoms that I should never ignore?
  • What are my treatment options?
    • Will the medicines interact with other medicines I am taking?
  • Should I change my diet?
  • Do I need to take time off from work?
  • When should I come back for a check-up?
  • How long will it take for me to stop having black stool?
  • Do I need to stop smoking?
    • If not, how often can I smoke?
    • If I need to stop smoking, how should I stop?
  • Do I need to stop drinking?
    • If not, how often can I drink?
    • Am I allowed to drink any type of alcohol?

Treatment for Black Stool

Treatment depends on the cause and severity of the bleeding. For serious bleeding, you may be admitted to a hospital for monitoring and workup. Workup may include blood tests, urine analysis and responses to eating different types of foods.

Prevent Black Stool

You can help prevent black stool by:

  • Reduce your risk of constipation, hemorrhoids, diverticulosis, and colon cancer by eating vegetables and foods rich in natural fiber and low in saturated fat
  • Avoid prolonged, excessive use of anti-inflammatory drugs like ibuprofen, naproxen, and aspirin
  • Limit alcohol intake
    • Large amounts of alcohol can irritate the lining of the esophagus and stomach
  • Do not smoke.
    • Smoking is linked to peptic ulcers and cancers of the GI tract