Why Do I Have Black Stool When Defecating?

Passing black stool may be caused by intestinal or gastric bleeding, recent consumption of iron-rich foods, esophageal cancer, esophageal varices, and other reasons. It is recommended to promptly visit a hospital to identify the cause and receive targeted treatment.

There are various reasons for gastric bleeding, commonly including peptic ulcer (such as gastric ulcer and duodenal ulcer), acute gastric mucosal lesion, and gastrointestinal malignancy. Severe bleeding can manifest as black stool and hematemesis. Therefore, it is necessary to exclude the influence of dietary factors and perform gastroscopy, colonoscopy, and enteroscopy if necessary.

If the stool is black, the first thing to consider is whether you have recently consumed a large amount of iron-rich foods, such as agaric, dried food, or duck blood. This can cause black stool due to excretion. This symptom is usually not a concern and can be relieved by improving the diet.

Black stool is one of the late manifestations of this malignant disease, with a male-to-female incidence ratio of 3:1. Progressive obstruction first manifests as painless dysphagia, followed by rapid weight loss. Patients may experience persistent chest pain with a feeling of fullness behind the sternum, nausea, vomiting, and hematemesis. Other symptoms include hoarseness, persistent cough (possibly bloody), hiccups, sore throat, and bad breath. Symptoms and signs in the late stages of the disease include painful dysphagia, decreased appetite, and reflux.

This life-threatening condition can lead to black stool, hematochezia, and hematemesis. The appearance of black stool precedes shock symptoms such as tachycardia, shortness of breath, hypotension, and cold clammy skin. Excitement or confusion may indicate hepatic encephalopathy.