Black or tarry stools, ground: what is this, causes, symptoms, diagnostics, treatment, prevention

Black or tarry stools; Stools – bloody; Mane; Stools – black or tarry; Upper gastrointestinal bleeding; Melenic stools

What is black stool

Black or tarry stools (mud) with an unpleasant odor is a sign of a problem in the upper digestive tract. Most often this indicates bleeding in the stomach., small intestine or right side of the large intestine.

The term melena is used to describe this phenomenon..

What causes black stool

The use of black licorice, blueberries, blood sausage or taking iron tablets, activated charcoal or drugs, containing bismuth (such as pepto-bismol), can also cause black stools. Beets and red-colored foods can sometimes make stools reddish.. In all these cases, the doctor may test the stool with a chemical., to rule out blood.

Bleeding in the esophagus or stomach (eg, with ulcers) can also cause blood to vomit.

Causes of black stool

The color of blood in the stool may indicate the source of the bleeding..

• Black or tarry stools may be due to bleeding in the upper gastrointestinal tract, such as the esophagus, stomach or first part of the small intestine. In this case, the blood is darker, because it is digested on its way through the gastrointestinal tract.
• Red or fresh blood in the stool (rectal bleeding) is a sign of bleeding from the lower gastrointestinal tract (rectum and anus).

Peptic ulcers are the most common cause of acute upper GI bleeding.. Black and tarry stools can also cause:

• Abnormal blood vessels in the esophagus, stomach or duodenum
• Rupture of the esophagus due to severe vomiting (Mallory-Weiss rupture)
• Blocking off the blood supply to part of the intestine
• Inflammation of the stomach lining (gastritis)
• Injury or foreign body in the gastrointestinal tract
• Dilated enlarged veins in the esophagus and stomach, usually caused by cirrhosis of the liver
• Esophageal carcinoma, stomach, duodenum or ampulla of Vater

When to contact a healthcare professional if you have black stools

Seek immediate medical attention, if:

• Have you noticed blood or a change in stool color?
• You vomit blood
• You feel dizzy or nauseous

In children, a small amount of blood in the stool is most often not a serious symptom.. The most common cause is constipation. You must still tell your child's doctor, if you notice this problem.

What to Expect When Visiting Doctors, if you have black stool

The doctor will take a medical history and conduct a physical examination. The study will focus on your abdomen.

You may be asked the following questions:

• Do you take blood thinners, such as aspirin, warfarin, elixir, prodaxa, xarelto or clopidogrel or similar drugs? You are taking NSAIDs, eg ibuprofen or naproxen?
• Have you had any injuries or accidentally swallowed a foreign object?
• Have you been eating black licorice, pepto-bismol or blueberries?
• Have you had more than one episode of blood in your stool?
• Have you lost weight lately?
• Blood is only visible on toilet paper?
• What color is the chair?
• When the problem arose?
• What other symptoms are present ( abdominal pain , vomiting blood, abdominal distention , excessive gas formation , diarrhea or fever )?

Diagnosis of the causes of black feces

Maybe, you will need to have one or more tests to find the cause of black stools. Analyzes may include the following procedures:

• Angiography
• Bleeding scan (nuclear medicine)
• Blood studies, including complete blood count and differential analysis, serum biochemical analysis, blood coagulation studies
• Colonoscopy
• Esophagogastroduodenoscopy or EGD
• Isolation of bacterial culture of stool
• Tests for Helicobacter pylori infection
• Capsule endoscopy (tablet with built-in camera, who takes video of the small intestine)
• Double balloon enteroscopy (probe, which can reach those parts of the small intestine, which are not available with EGD or colonoscopy)

Severe cases of bleeding, causing excessive blood loss and a drop in blood pressure, may require surgery or hospitalization.

Used sources and literature

Chaptini L, Peikin S. Gastrointestinal bleeding. In: Parrillo I, Dellinger RP, eds. Critical Care Medicine: Principles of Diagnosis and Management in the Adult. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 72.

DeGeorge LM, Nable JV. Gastrointestinal bleeding. In: Walls RM, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 26.

Kovacs TO, Jensen DM. Gastrointestinal hemorrhage. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 126.

Savides TJ, Jensen DM. Gastrointestinal bleeding. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 20.