Black Stools
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Reviewed By:

Samantha Nazareth, MD

Samantha Nazareth, MD (Gastroenterology)

Board-certified gastroenterologist. Experience managing gastrointestinal conditions (GERD, IBS, ulcerative colitis, Crohn’s, celiac disease, NASH) within healthcare organizations (three ambulatory surgical centers, single-specialty practice, multi-specialty practice and solo practice).

Aiko Yoshioka, MD

Aiko Yoshioka, MD (Gastroenterology)

Dr. Yoshioka graduated from the Niigata University School of Medicine. He worked as a gastroenterologist at Saiseikai Niigata Hospital and Niigata University Medical & Dental Hospital before serving as the Deputy Chief of Gastroenterology at Tsubame Rosai Hospital and Nagaoka Red Cross Hospital. Dr. Yoshioka joined Saitama Saiseikai Kawaguchi General Hospital as Chief of Gastroenterology in April 2018.

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  • Ink-like stool appeared only once

  • Black stool came out only once

  • Poop is black like coal

  • Poop was black only once

  • Black stool only once

  • Black poop only once

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Content updated on Nov 26, 2023

About the symptom

Black stool is also called melena and is often described as tarry in texture and foul smelling. The blood is darker because it has been digested. It can be caused by bleeding in the upper part of the gut or ingesting iron supplements, bismuth (found in Pepto-Bismal) or certain foods, like black licorice.

When to see a doctor

Seek professional care if you experience any of the following symptoms

  • Fever

  • Dizziness

  • Fainting with loss of consciousness

  • Sickly/pale appearance

  • Vomiting of blood

  • Unexplained weight loss of 5% or more in 1 month

  • Jaundice

  • Edema

  • Recent weight loss

Possible causes

  • Gastroduodenal ulcer

    Ulcers are sores that can develop in the stomach and small intestines. In severe cases, the ulcers can be deep and cause bleeding within the gut wall. Common causes include the bacteria H. pylori, and painkillers such as Diclofenac, Ibuprofen, Naproxen, Advil, Aleve (NSAIDs).

  • Esophageal cancer

    Cancer of the esophagus (the tube that carries food from the throat to the stomach). The primary symptom is worsening trouble with swallowing or a feeling that something is stuck in the food tube. Sometimes people have weight loss and fatigue as well. It is diagnosed when a doctor, usually a gastroenterologist, puts a tube with a camera down the throat while the patient is sleeping and takes a biopsy of any abnormality they see in the esophagus. Once the cancer has been diagnosed by biopsy, CT scans, PET scans and MRIs may be ordered as well. Known risk factors include alcohol, smoking, a condition called "Barrett esophagus," gastric acid reflux and age.

  • Zollinger-Ellison syndrome

    Zollinger-Ellison Syndrome is a rare condition where one or more tumors in the stomach, known as gastrinomas, result in the production of too much gastric acid. The excessive acid may cause peptic ulcers in your stomach or intestine, resulting in symptoms such as heartburn, abdominal pain, acid reflux, and vomiting. Some people with this condition may have a genetic problem known as multiple endocrine neoplasia type 1 (MEN1).

  • Vasculitis syndrome (including cryoglobulinemia)
  • Anemia
  • MALT lymphoma
  • Helicobacter pylori infection
  • GIST

Related serious diseases

Questions your doctor may ask about this symptom

Your doctor may ask these questions to check for this symptom

  • Are your stools black and shiny like hair?

  • Do you have a stomach ache?

  • Do you have loose stools or diarrhea?

  • Are you feeling nauseous or have you been vomiting?

  • Did you vomit blood?

Other Related Symptoms

Similar symptoms or complaints

References

  • National Library of Medicine. (2020)

    https://medlineplus.gov/ency/article/003130.htm

Reviewed By:

Samantha Nazareth, MD

Samantha Nazareth, MD (Gastroenterology)

Board-certified gastroenterologist. Experience managing gastrointestinal conditions (GERD, IBS, ulcerative colitis, Crohn’s, celiac disease, NASH) within healthcare organizations (three ambulatory surgical centers, single-specialty practice, multi-specialty practice and solo practice).

Aiko Yoshioka, MD

Aiko Yoshioka, MD (Gastroenterology)

Dr. Yoshioka graduated from the Niigata University School of Medicine. He worked as a gastroenterologist at Saiseikai Niigata Hospital and Niigata University Medical & Dental Hospital before serving as the Deputy Chief of Gastroenterology at Tsubame Rosai Hospital and Nagaoka Red Cross Hospital. Dr. Yoshioka joined Saitama Saiseikai Kawaguchi General Hospital as Chief of Gastroenterology in April 2018.

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