Blood as seen in the stool can originate anywhere along the intestinal tract. Black stool usually means that the blood is coming from the upper part of the GI tract. The following may be the causes:
- bleeding ulcer
- gastritis
- esophageal varices
- a tear in the esophagus from violent vomiting
Maroon-colored bowel movements or bright red blood usually suggest that the blood is coming from large bowel or rectum.
- all the causes of black color stool
- diverticular bleeding
- vascular malformation
- intestinal infection (such as bacterial enterocolitis)
- inflammatory bowel disease
- tumor
- colon polyps or colon cancer
- Some upper GI causes may result to vomiting blood such as in peptic ulcer disease.
- Red blood in the stool might be due to hemorrhoids.
- Amebiasis, anal fissures, or colorectal cancer.
- Colonic polyps or tumors, diverticulosis,
- Abnormal small vessels called AVMs
- Melena, if at least 6 Tablespoons (or 200 milliliters) of blood is lost
Bright red color -
- all the causes of black or maroon color stool
- hemorrhoids
- anal fissures ("cracks" in the anal area)
Diagnostic Tests for Bloody Bowel Movements
- Colonoscopy
- The color of the stool can suggest the location of the bleeding however this is not reliable.
- A definitive diagnosis will require radiographic and/or endoscopic investigation.
