Bloody or tarry stools refer to a stool sample that’s either dark
red or black in color. Bloody or tarry stools can indicate bleeding or other
injuries in your gastrointestinal tract. You may also have dark, discolored
bowel movements after eating dark-colored foods. Notify your doctor any time
you have bloody or black-colored stool to rule out serious medical conditions.
Causes Black, Tarry Stools?
Black, Tarry Stools
Bleeding in the upper portion of your digestive system can cause
black, tarry stools. Ulcers or another form of irritation in your esophagus or
stomach known as gastritis can
cause bleeding. When the blood mixes with digestive fluids, it takes on the
appearance of tar.
Certain medications can also lead to black-colored stools. Iron
supplements and bismuth-based medications, for example, can darken your stools.
Sometimes, serious blood and circulation abnormalities in your
digestive system can cause black, tarry stools. These can include the
- Bowel ischemia is a reduction of blood flow to
- Vascular malformation is misshapen veins.
- Varices are large, protruding veins in the
Red, Bloody Stools
Red or bloody stools can also be due to several different medical
conditions. Your stools may be bloody due to bleeding in the lower half of your
digestive system. Cancerous or benign polyps on your colon can produce gastrointestinal bleeding in
some cases. Inflammatory bowel diseases such as diverticulosis, ulcerative
colitis, and Crohn’s disease may cause you to expel bright red or
maroon-colored blood in your stool.
A common cause of bloody stools is the presence of hemorrhoids. Hemorrhoids are swollen
veins located in your rectum or anus. Straining to produce a bowel movement can
Blockages at any point in your digestive tract can cause black,
tarry, or bloody stools.
The foods you eat can cause your stools to appear bloody or
tarry. Eating red or black foods can give your feces a dark appearance without
the existence of blood.
The following can discolor your bowel movements:
- black licorice
- dark chocolate cookies
- red-colored gelatin
- red fruit punch
Is the Cause of Bloody or Tarry Stools Diagnosed?
Your doctor will take a medical history and perform a physical
examination to determine the cause of your unusual stool color. They’ll
probably order blood tests and a stool sample. Imaging tests such as MRIs,
X-rays, and CT scans can help them see the blood flow to your digestive system.
These diagnostic tools will reveal any blockages that could be causing
Your doctor may schedule a colonoscopy to assess the condition of
your colon. A colonoscopy often occurs
while you’re under sedation. Your doctor will use a thin, flexible tube with a
camera on the end to see the inside of your colon and look for the cause of
Are the Treatment Options for Bloody or Tarry Stools?
The treatment of bloody or tarry stools varies according to the
cause of the problem. According to the American
Cancer Society, people with cancer who have hemorrhoids can ease the
passage of stool and reduce bleeding by using stool softeners under a doctor’s
direction. Sitz baths can also ease the pain of hemorrhoids and prevent
Your doctor may prescribe acid-reducing medications to treat
bleeding ulcers. Antibiotics and immunosuppressant drugs can also calm
inflammatory bowel disease and infections.
Vein abnormalities and blockages may require surgical repair if
the bleeding doesn’t stop on its own. If you’ve lost a lot of blood through your
stool, you may be at risk of developing anemia. You may need a blood
transfusion to replenish your supply of red blood cells.
Polyps on your colon that cause bloody stools can indicate
precancerous conditions or cancer in some people. Your doctor will determine
the appropriate treatment for these conditions. Removal of the polyps may be
all that’s necessary in some cases. Other polyps may require radiation therapy
and chemotherapy if cancer is present.
How Can I Prevent Bloody or Tarry Stools?
You can help lessen the occurrence of bloody or tarry stools by
drinking plenty of water and eating lots of fiber. Water and fiber help soften
stool, which can ease the passage of stool from your body. Some foods that have
- whole grains
However, consult your doctor to decide on a high-fiber diet that
will work with your underlying cause or condition. For example, berries can be
irritating if you have an inflammatory, gastric condition.