Why is my stool black?
Disease description:
I had some diarrhea when I went to the bathroom today, and the stool was black. However, there was no abdominal pain. I would like to know what might be causing this situation.
Doctor's answer (1)
Dr. Shen Yonghua
Black stool, commonly referred to as melena, can be caused by several factors including but not limited to the following:
1. Dietary factors: Consuming large amounts of iron-rich foods within a short period, such as blood tofu, pork liver, and lean meat, or eating certain dark-colored foods like Oreo cookies and black sesame seeds, may cause black-colored stool. Additionally, taking certain medications, such as iron supplements or bismuth preparations, can also lead to darkening of the stool.
2. Gastrointestinal bleeding: Bleeding from the upper gastrointestinal tract is a common cause of black stool. When blood remains in the intestines for a prolonged period, the iron in hemoglobin is converted into iron sulfide through the action of intestinal bacteria, resulting in black-colored stool. In such cases, the melena often has a distinctive foul odor and the stool may appear tarry.
3. Other gastrointestinal diseases: Such as gastritis, gastric ulcers, and ruptured esophageal varices with bleeding.
If persistent black stool occurs, especially when accompanied by symptoms such as abdominal pain, vomiting, or weight loss, immediate medical attention and evaluation are necessary.
