What causes black stool?

In general, black stools may be related to factors such as food staining, taking iron-containing medications or supplements, gastric ulcer bleeding, colorectal polyps, or liver cirrhosis. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under the guidance of a qualified physician. Specific analyses are as follows:

1. Food Staining

Consuming certain dark-colored foods such as mulberries or black sesame seeds may result in incomplete breakdown of natural pigments during digestion, potentially causing stool to appear black. No special treatment is required; adjusting the diet and reducing intake of these foods will typically return stool color to normal.

2. Taking Iron-Containing Medications or Supplements

Long-term or excessive use of iron-containing medications or supplements may lead to iron combining with sulfides in the intestines to form black ferric sulfide, resulting in darkened stool. Usually, no specific treatment is needed. Dosage adjustments or alternative iron supplementation methods can be made under a doctor’s guidance.

3. Gastric Ulcer Bleeding

Gastric ulcer bleeding is primarily caused by prolonged exposure to unhealthy lifestyle habits or irritants, which may lead to repeated damage of the gastric mucosa by stomach acid, resulting in gastrointestinal bleeding. As blood passes through the digestive tract, it is acted upon by digestive enzymes and is excreted as black, tarry stools (melena). This condition may be accompanied by symptoms such as upper abdominal pain, nausea, and vomiting. Patients may be prescribed medications such as omeprazole enteric-coated capsules, pantoprazole sodium enteric-coated tablets, or aluminum magnesium carbonate chewable tablets under medical supervision.

4. Colorectal Polyps

The development of colorectal polyps is often associated with insufficient dietary fiber intake and weakened immune function, which may trigger inflammatory responses in the intestine, leading to the gradual formation of granulomatous, polyp-like growths on the intestinal mucosa. These polyps may bleed when irritated or damaged, mixing blood with feces and resulting in black stools. Symptoms may include abdominal pain and diarrhea. Treatment may involve medications such as cefixime granules, ciprofloxacin hydrochloride tablets, or amoxicillin capsules, as directed by a physician.

5. Liver Cirrhosis

Nutritional deficiencies and malnutrition may chronically impair liver health, leading to hepatocyte damage. Damaged liver cells may promote proliferation of fibrous tissue within the liver, compressing intrahepatic blood vessels and potentially causing vessel rupture and bleeding. Blood entering the intestines mixes with stool and is excreted as black stools. Additional symptoms may include fatigue and abdominal distension. Treatment under professional medical guidance may include medications such as entecavir tablets, diammonium glycyrrhizinate capsules, or polyene phosphatidylcholine capsules.

It is advisable to cultivate healthy daily habits, maintain a balanced diet, enhance immune function, and support normal gastrointestinal motility to promote overall digestive health.