Gastrointestinal (GI) bleeding refers to any bleeding that starts in the gastrointestinal tract, which extends from the mouth to the anus.

The amount of bleeding can range from nearly undetectable to acute, massive, and life threatening.

Bleeding may come from any site along the GI tract, but is often divided into:

• Upper GI bleeding: The upper GI tract is located between the mouth and the upper part of the small intestine.
• Lower GI bleeding: The lower GI tract is located between the upper part of the small intestine and the anus. The lower GI tract includes the small and large bowels.

GI bleeding can range from microscopic bleeding (the amount of blood is so small that it can only be detected by laboratory testing) to massive bleeding (pure blood is passed).

It is important to be aware of GI bleeding, because it may point to many significant diseases and conditions. Prolonged microscopic bleeding can lead to loss of iron, causing anemia. Acute, massive bleeding can lead to hypovolemia, shock, and even death.

GI bleeding can occur at any age from birth on. The degree and suspected location of the bleeding determines what tests should be performed to find the cause. Once a bleeding site is identified, many therapies are available to stop the bleeding.

Some of the possible causes of GI bleeding include:

• Anal fissure
• Aorto-enteric fistula
• Arterio-venous malformations (also called angiodysplasias)
• Bleeding diverticulum
• Cancer of the small intestine
• Celiac sprue
• Colon cancer
• Cow's milk allergy
• Crohn's disease
• Dieulafoy's lesion
• Duodenal ulcer
• Dysentery (infectious diarrhea that causes bleeding)
• Esophageal varices
• Esophagitis
• Gastric (stomach) ulcer
• Hemorrhoids
• Ischemic bowel
• Intestinal polyps
• Intestinal obstruction (twisted bowel)
• Intestinal vasculitis
• Intussusception (bowel telescoped on itself)
• Mallory-Weiss tear
• Meckel's diverticulum
• Nosebleed
• Portal hypertensive gastropathy
• Radiation injury to the bowel
• Stomach cancer
• Ulcerative colitis

There are home stool tests for microscopic blood that may be recommended for people with anemia or for colon cancer screening.

Call for an appointment with your doctor if:

• You have black, tarry stools (this may be a sign of upper GI bleeding)
• You have blood in your stool
• You vomit blood or you vomit material that looks like coffee grounds

GI bleeding is diagnosed by a doctor -- you may or may not be aware of its presence.

GI bleeding can be an emergency condition requiring immediate medical attention. Treatment may involve:

• Blood transfusions
• Fluids and medicines through a vein
• Tube through the mouth into the stomach to drain the stomach contents (gastric lavage)

Once the condition is stable, a physical examination, including a detailed abdominal examination, will be performed.

You will also be asked questions about your symptoms, including:

• When did you first notice symptoms?
• Did you have black, tarry stools or red blood in the stools?
• Have you vomited blood?
• Did you vomit material that looks like coffee grounds?
• Do you have a history of peptic or duodenal ulcers?
• Have you ever had symptoms like this before?
• What other symptoms do you have?

Tests that may be done include:

• Abdominal CT scan
• Abdominal MRI scan
• Abdominal x-ray
• Angiography
• Bleeding scan (tagged red blood cell scan)
• Capsule endoscopy (camera pill that is swallowed to look at the small intestine)
• Colonoscopy
• Complete blood count (CBC), clotting tests, platelet count, and other laboratory tests
• EGD
• Enteroscopy
• Sigmoidoscopy

Bjorkman D. GI hemorrhage and occult GI bleeding. In: Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 137.