Blood in stool can vary in color and indicate different sources of bleeding in the digestive tract:
- Bright red blood – Typically from the lower colon, rectum, or anus.
- Dark red or brown blood – Usually originates from the higher colon or small intestine.
- Black (melena) – Suggests bleeding in the upper gastrointestinal (GI) tract, such as from a stomach ulcer.
- Occult bleeding – Invisible to the naked eye but detectable under a microscope.
Certain foods (e.g., beets, tomatoes, blackberries) and supplements (e.g., iron or multivitamins) can alter stool color, mimicking blood.
Common Causes of Blood in Stool
- Hemorrhoids – Swollen rectal veins, often leading to minor bleeding.
- Anal fissures – Small tears in the anal lining, often caused by passing hard stools.
- Inflammatory Bowel Disease (IBD) – Chronic inflammation in the digestive tract, including conditions like ulcerative colitis and Crohn’s disease.
- Peptic Ulcers – Open sores in the stomach or duodenum, commonly caused by H. pylori infection or prolonged NSAID use.
- Polyps or Colorectal Cancer – Abnormal growths that may bleed and, in some cases, become cancerous.
- Diverticular Disease – Small pouches in the colon that can become infected or bleed.
- Gastroenteritis – Infections from bacteria like E. coli, Salmonella, Shigella, and Campylobacter can lead to bloody diarrhea, nausea, and vomiting.
If blood in stool persists or is accompanied by other concerning symptoms (pain, weight loss, fatigue), medical evaluation is essential for proper diagnosis and treatment.
