Black or Tarry Stool

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

Generally, Black or tarry stool can be related to:

• 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 (including Cryoglobulinemia)
• Gastric Cancer
• Meckel's Diverticulosis

Related Serious Diseases

Sometimes, Black or tarry stool may be related to these serious diseases:

• Esophageal Varices Rupture

  Rupture of blood vessels in the esophagus (food pipe), leading to significant bleeding. This typically occurs in advanced liver disease when veins enlarge due to high pressure.

• Perforated Peptic Ulcer

• Infective Endocarditis
• Idiopathic Esophageal Rupture

Doctor's Diagnostic Questions

Your doctor may ask these questions to check for this symptom:

• Have you had black, shiny stools?
• How often do you have a black, shiny stool?
• Did you have black, shiny stools once?
• How long have you had black, shiny stools?

Find Similar Symptoms

References

• National Library of Medicine. (2020)

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