Stool color is mainly determined by what you eat (including foods and medications) and the presence of bile, which is a yellow-green fluid that helps with fat digestion.
Dark stools can be caused by foods such as:
- Black licorice
- Blueberries
- Beets
- Blood sausage
- Dark-colored food dyes or colors
What does it mean if my stools are dark?
Dark stools could be caused by certain medications or health conditions.
Black or tarry stools, also called melena, occur due to the presence of blood in your gut. This is usually caused by bleeding in the upper gastrointestinal (GI) tract, such as the esophagus, stomach, or small bowel. Bleeding may occur due to radiotherapy or following an endoscopy. When bleeding occurs from the lower GI tract, such as the colon or rectum, it may appear as fresh blood (called hematochezia).
Causes of black or tarry stools include:
- Medications
- Nonsteroidal anti-inflammatory drugs
- Aspirin
- Blood thinners
- Pepto-Bismol (bismuth subsalicylate)
- Iron supplements
- Activated charcoal
- Medical conditions
- Bleeding peptic ulcer
- Tears in the esophageal or gastric lining
- Esophageal varices (swollen veins in the esophagus)
- Gastritis (inflammation of the stomach)
- Esophagitis (inflammation of the esophagus)
- Injury to the upper GI tract due to procedures, such as endoscopy
- Foreign body in the upper GI tract
- Parasite infections
- Upper GI cancer (such as stomach or esophageal cancer)
Is very dark brown stool normal?
Dark stools that go away when you stop taking certain foods or medications are generally not a cause for concern. For example, small amounts of blood may appear in stools in case of constipation, particularly in children.
However, consult your doctor if you notice the following symptoms, as they could be a sign of a more serious condition:
- Blood in stools or vomit
- Abdominal pain
- Abdominal tenderness
- Fever
- Dizziness
- Fatigue
- Unexplained weight loss
How do doctors diagnose the cause of dark stools?
- Medical history: You may be asked about when your symptoms started, your dietary habits, whether you are taking any medications or supplements, personal or family history of cancer, a history of procedures or radiotherapy on your gut, and accompanying symptoms.
- Physical examination: This may include a general examination to look for any signs of anemia, jaundice, or swelling (edema) in the body. Your doctor may examine your abdomen for distention, lumps, and bowel sounds.
- Tests: Diagnostic tests may include:
- Blood counts
- Liver function tests, including a clotting test
- Stool examination for occult blood or the presence of any infection, including H. pylori or any parasites
- Angiography
- Urea breath test (for H. pylori)
- Red blood cell nuclear scan
- Ultrasound of the abdomen
- Endoscopy
- Biopsy
SLIDESHOW
Super Tips to Boost Digestive Health: Bloating, Constipation, and More See SlideshowMedically Reviewed on 12/1/2022
References
Image Source: Getty image
Why Is Your Poop Black and Tarry? https://www.webmd.com/digestive-disorders/black-tarry-stool-reasons
Tests for H pylori. https://medlineplus.gov/ency/article/007501.htm
Why Is Your Poop Black and Tarry? https://www.webmd.com/digestive-disorders/black-tarry-stool-reasons
Tests for H pylori. https://medlineplus.gov/ency/article/007501.htm
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