Diseases & Conditions

Bleeding in the Gut - Gastrointestinal Bleeding

Overview, Causes, & Risk Factors

Gastointestinal (GI) bleeding describes any blood loss that occurs through the digestive tract.

What is going on in the body?

The GI or digestive tract is a passage that leads from the mouth to the anus. This tract also includes the:

  • esophagus, a tube that connects the mouth to the stomach
  • stomach
  • intestines
  • Bleeding can occur anywhere in the GI tract due to various conditions.

    What are the causes and risks of the condition?

    There are many possible causes of this condition, including:

  • peptic ulcer, which may occur in the stomach or small intestine
  • gastritis, or inflammation of the lining of the stomach. This often occurs in those who have been using aspirin or pain medications called nonsteroidal anti-inflammatory drugs (NSAIDs). Gastritis is also common in a person who is alcohol dependent.
  • enlarged veins in the esophagus called esophageal varices, which are prone to rupturing. This condition is usually seen as a part of alcoholic liver disease.
  • a Mallory-Weiss tear, which is a small tear in the inside lining of the esophagus, usually due to severe retching or vomiting
  • diverticulosis, a condition that causes outpouchings of the walls of the colon
  • infections in the gut, such as certain forms of infection-related diarrhea, or diverticulitis, an infection of the outpouchings that occur in diverticulosis
  • cancers or tumors, such as colon cancer, stomach cancer, or esophageal cancer
  • inflammatory bowel disease, a poorly understood condition that results in inflammation in the bowels
  • hemorrhoids, which are enlarged veins around the anus
  • abnormal blood vessels in the digestive tract, which may rupture
  • inflammation of the colon from a lack of blood flow, or from radiation therapy
  • Other causes are also possible. Sometimes, no cause can be found.

    Symptoms & Signs

    What are the signs and symptoms of the condition?

    Mild cases of bleeding may cause no symptoms at all. When symptoms are present, they are related to the cause of blood loss, as well as the amount and location of the blood loss. Common symptoms include:

  • noticeable blood loss, such as blood in the stools or vomiting blood. Stools may also become black and sticky, a condition known as melena.
  • symptoms of anemia, or low red blood cell counts, from too much blood loss. These symptoms may include fatigue, weakness, shortness of breath, dizziness, or pale skin.
  • Other symptoms are often related to the cause. For example:

  • peptic ulcers can cause abdominal distress
  • colon cancer can cause weight loss

  • Diagnosis & Tests

    How is the condition diagnosed?

    Bleeding in the GI tract may be discovered with a routine test of the stool for blood that is often part of a complete physical exam. In other cases, a person complains of blood in the stool. In some cases, the history and physical exam are all that is needed to determine the cause, such as with visible hemorrhoids.

    In most cases, further testing is needed, and may include:

  • a CBC, or complete blood count
  • endoscopy to locate the source of bleeding. This is a procedure that uses a thin tube with a light and camera on the end of it. The tube can be inserted into the mouth or anus and advanced into the GI tract. The camera on the end of the tube allows the provider to see the inside lining of the GI tract.
  • special x-ray tests or additional tests to detect bleeding

  • Prevention & Expectations

    What can be done to prevent the condition?

    Avoidance of alcohol, aspirin, and NSAIDs can prevent cases due to these causes. Many cases cannot be prevented.

    What are the long-term effects of the condition?

    Heavy, rapid bleeding can result in shock or death. Most long-term effects are related to the cause of GI bleeding. For example, hemorrhoids may be painful, but rarely cause serious long-term effects. Cancer can cause death.

    What are the risks to others?

    GI bleeding is not contagious. In cases due to infections, the infection is sometimes contagious.

    Treatment & Monitoring

    What are the treatments for the condition?

    Those with heavy bleeding may need blood transfusions. Fluids may be given through a an intravenous line, which is a thin tube inserted into a person's vein. Further treatment is often directed at the cause, if it can be determined. For example, those with:

  • ulcers may need medications to reduce stomach acid, such as ranitidine or omeprazole
  • cancer may need surgery, chemotherapy, or radiation therapy
  • an infection may need antibiotics
  • What are the side effects of the treatments?

    Side effects depend on the treatments used:

  • Blood transfusions may cause allergic reactions or infections.
  • Antibiotics may cause allergic reactions and stomach upset.
  • Surgery carries a risk of infection and bleeding.
  • What happens after treatment for the condition?

    Some people may die even with treatment if the bleeding is heavy and cannot be stopped. This is not uncommon in those with bleeding from esophageal varices. Some people are able to return to normal activities right away, such as most people with hemorrhoids.

    How is the condition monitored?

    Periodic CBC blood tests may be done to make sure the blood counts are stable. Many people with bleeding are briefly monitored for further bleeding in the hospital. Other monitoring is usually related to the cause. For example, those with a stomach ulcer may need a repeat endoscopy procedure in the future to make sure the ulcer is healing properly.


    Author:Adam Brochert, MD
    Date Written:
    Editor:Coltrera, Francesca, BA
    Edit Date:07/20/00
    Reviewer:Gail Hendrickson, RN, BS
    Date Reviewed:08/07/01


    The Merck Manual, 1995, Berkow et al.