Bloody or tarry stools

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Lower digestive anatomy

Overview

Treatment

Bloody or tarry stools

Definition:

Bloody stools often indicate an injury or disorder in the digestive tract. Your doctor may use the term "melena" to describe black, tarry, and foul-smelling stools or "hematochezia" to describe red- or maroon-colored stools.

Alternative Names:
Stools - bloody; Hematochezia; Melena; Stools - black or tarry
Considerations:

text continues below

Blood in the stool may come from anywhere along your digestive tract, from mouth to anus. It may be present in such small amounts that you cannot actually see it, but is only detectable by a fecal occult blood test. When there IS enough blood to change the appearance of your stools, the doctor will want to know the exact color tohelp findthe site of bleeding. To make a diagnosis, your doctor may use endoscopy or special x-ray studies.

A black stool usually means that the blood is coming from the upper part of the gastrointestinal (GI) tract. This includes the esophagus, stomach,and thefirst part of the small intestine. Blood will typicallylook like tar after it has been exposed to the body's digestive juices. Stomach ulcers caused by ibuprofen, naproxen, or aspirin are common causes of upper GI bleeding.

Maroon-colored stools or bright red blood usually suggest that the blood is coming from the lower part of the GI tract (large bowel or rectum). Hemorrhoids and diverticulitis (inflammation of an abnormal pouch in the colon) are the most common causes of lower GI bleeding. However, sometimes massive or rapid bleeding in the stomach causes bright red stools.

Consuming black licorice, lead, iron pills, bismuth medicines like Pepto-Bismol, or blueberries can also cause black stools. Beets and tomatoes can sometimes make stools appear reddish. In these cases, your doctor can test the stool with a chemical to rule out the presence of blood.

Brisk bleeding in the esophagus or stomach (such as with peptic ulcer disease), can also cause you to vomit blood.

Common Causes:

Upper GI tract (usually black stools):

Bleeding stomach or duodenal ulcer
Gastritis
Esophageal varices
Mallory-Weiss tear (a tear in the esophagus from violent vomiting)
Trauma or foreign body
Bowel ischemia (a lack of proper blood flow to the intestines)
Vascular malformation

Lower GI tract (usually maroon or bright red, bloody stools):

Hemorrhoids
Anal fissures
Diverticular bleeding
Intestinal infection (such as bacterial enterocolitis)
Vascular malformation
Inflammatory bowel disease
Tumor
Colon polyps or colon cancer
Trauma or foreign body
Bowel ischemia (a lack of proper blood flow to the intestines)

References:

Green BT, Tendler DA. Ischemic Colitis: A Clinical Review. South Med J. 2005; 98 (2): 217-222.

Cappell MS. The role of sigmoidoscopy and colonoscopy in the diagnosis and management of lower gastrointestinal disorders: technique, indications, and contraindications. Med Clin North Am. 2002; 86(6): 1217-1252.