What Causes Black Stool?

Black stool should first prompt consideration of dietary causes. For instance, recent consumption of foods such as pork blood, lamb blood, duck blood, or pig liver can lead to black stool—this is a normal physiological phenomenon. Secondly, certain medications may be responsible. Some individuals with underlying health conditions require medication for treatment or regulation, and certain drugs themselves are dark-colored; their excretion may darken the stool. If black stool resolves after discontinuing the medication, it is likely drug-induced and generally not a cause for concern—a benign, reversible effect.

Pathologically, black stool is commonly associated with gastrointestinal disorders—for example, peptic ulcers or acute gastritis. Additionally, certain infectious diseases—including sepsis and typhoid fever—may also cause melena. If black stool occurs consistently after daily alcohol consumption—and no black-stool-inducing foods or medications have been ingested—it is advisable to consult a healthcare provider for routine stool analysis and fecal occult blood testing. Upper gastrointestinal endoscopy (gastroscopy) may further help identify the underlying cause. Patients should adhere to a light, bland diet, avoid smoking and alcohol, and refrain from overeating or binge eating.