Black Stool: What Are The Possible Causes

Black stool should never be ignored as it can indicate a serious health condition. When a person passes tarry, black stool, it often suggests the presence of upper gastrointestinal bleeding. Common causes of upper gastrointestinal bleeding include peptic ulcers, stomach cancer, esophageal varices, and acute gastric mucosal lesions. Each of these conditions carries its own risks and should be taken very seriously.

Understanding Upper Gastrointestinal Bleeding

Peptic ulcers are sores that develop on the lining of the stomach or the first part of the small intestine. These ulcers can bleed slowly over time, leading to black stools. Similarly, gastric cancer may cause internal bleeding in the stomach, which can also lead to dark-colored feces.

Esophageal and gastric varices are enlarged veins in the esophagus or stomach that can rupture and bleed heavily. This condition is often associated with liver diseases such as cirrhosis. Another condition, acute gastric mucosal lesions, can occur due to severe stress, trauma, or critical illness and may lead to bleeding in the stomach lining.

Non-Medical Reasons For Black Stool

In some cases, black stool may not be caused by internal bleeding at all. Certain foods and medications can also darken the stool. For example, iron supplements, bismuth-containing medications (like Pepto-Bismol), consumption of animal liver, or ingestion of blood from a nosebleed can all cause the stool to appear darker than usual.

How To Differentiate Between Medical and Non-Medical Causes

To determine whether the black stool is due to bleeding or dietary factors, a fecal occult blood test is often performed. This test detects the presence of hemoglobin in the stool and can help rule out or confirm gastrointestinal bleeding. Unlike dietary changes, blood in the stool will show a positive result on the occult blood test.

What To Do If You Notice Black Stool

If someone experiences black, tarry stools, they should seek medical attention immediately. A visit to the emergency room is often necessary for a full evaluation. Doctors may perform a variety of tests including blood tests, stool tests, ultrasound imaging, and endoscopy to identify the underlying cause.

Once a diagnosis of gastrointestinal bleeding is confirmed, treatment typically involves the use of proton pump inhibitors (PPIs) to reduce stomach acid, hemostatic agents to stop the bleeding, and gastric mucosal protectants to promote healing of the stomach lining.