Patient's question:
In the past few days, every time I go to the toilet, I've noticed that the stool coming out is black, but there's nothing else that feels wrong. Also, my menstrual cycle has been irregular recently. What could be the factors or causes for this?Doctor's answer:
Hello, black stools are a symptom of upper gastrointestinal bleeding. In patients with upper gastrointestinal bleeding, about half are due to ulcer bleeding, of which about three-fourths are duodenal ulcer bleeding. Colon, rectum, hemorrhoids, anal fissures, and other anal and intestinal lesions can also cause bleeding, typically presenting as dark red or fresh blood in the stool. However, when the bleeding volume is small, the intestinal stimulation is minimal, and intestinal peristalsis is slow, the blood stays in the intestine for a longer period, during which hemoglobin iron is converted into black ferric sulfide, leading to the excretion of black stools.Advice:
When lesions occur in the colon, rectum, hemorrhoids, or anal fissures, bleeding may also occur, usually presenting as dark red or fresh blood in the stool. However, when the bleeding volume is small, the intestinal stimulation is minimal, and intestinal peristalsis is slow, the blood stays in the intestine for a longer period, during which hemoglobin iron is converted into black ferric sulfide, leading to the excretion of black stools.