Gastrointestinal bleeding refers to any bleeding that originates in the gastrointestinal tract, from the mouth to the large bowel. The degree of bleeding can range from nearly undetectable to acute, massive, life-threatening bleeding. Bleeding may originate from any site along the gastrointestinal tract, but is often divided into Upper GI bleeding (considered any source located between the mouth and outflow tract of the stomach), Lower GI bleeding (considered any source located from the outflow tract of the stomach to the anus, small and large bowel included)
Other Names for GI Bleeding.
Lower GI bleeding; GI bleeding; Upper GI bleeding
Many individuals have small amount of gastrointestinal bleeding ranging from microscopic bleeding, where the amount of blood is so small that it can only be detected by laboratory testing, to massive bleeding where pure blood is passed.
It is important to be aware of gastrointestinal bleeding, because it may herald many significant diseases and conditions. Prolonged microscopic bleeding can lead to massive losses of iron and subsequent anaemia. Acute, massive bleeding can lead to acute hypotension, unconsciousness and even death.
Gastrointestinal 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, numerous therapies are available to stop the bleeding.
Diagram 1, below shows the main parts of the GI tract which are likely to bleed.
Diagram 1. Parts of the GI tract which are most likely to bleed.
Causes of Upper Gastrointestinal bleeding.
GI Bleeding is divided into two types, for the purposes of this article, bleeding which occurs in any part of the GI tract from the mouth to the outflow tract of the stomach, is called upper GI Bleed. The causes of upper GI bleeding are different from those of lower GI bleed which will be discussed later.Upper GI bleeding
- Peptic Ulcer disease and peptic ulcer are localized erosions of the wall of the stomach. Ulcers in this region are a frequent occurrence. The breakdown of the walls results in damage to blood vessels, causing bleeding, which may be microscopic of massive. When the mucous membranes break down, they are unable to counteract the harsh effects of stomach acid. Nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, alcohol, and cigarette smoking promote gastric ulcer formation. These are the most common causes of GI bleeding. Some types of bacteria also promote formation of ulcers.
- General inflammation of the stomach wall, which can result in bleeding. Gastritis also results from an inability of the gastric lining to protect itself from the acid it produces. NSAIDs, steroids, alcohol, and trauma can cause gastritis.
- Esophageal varices: Swellings in veins of your esophagus or stomach usually result from liver disease. Varices most commonly result from alcoholic liver. When varices bleed, the bleeding can be massive and catastrophic and occur without warning.
- Mallory-Weiss tear: A tear in the esophageal or stomach wall, often as a result of vomiting or retching. Tears also can occur after seizures, forceful coughing or laughing, lifting, straining, or childbirth. Physicians often find tears in people who have recently binged on alcohol.
- Clot Busting medications used in the treatment / management of myocardial ischaemia, coronary artery occlusion, cerebral ischemia / occlusion can cause massive bleeding in the GI system.
- Steroids like prednisolone can induce bleeding in some patients.
Causes of Lower Gastrointestinal bleeding.
- Diverticula are one of the most common causes of lower GI bleeding. Small out-pockets, or diverticula, form on part of the wall of your colon (large intestine), usually in a weakened area of the bowel wall. Any individual can develop several pockets, which are more common in people who have and strain at stool.
- Angiodysplasia: This is one of the most common causes of lower GI bleeding. Angiodysplasia is a malformation in the blood vessels in the wall of the GI tract. The sores are most common in the large intestine and often bleed. The elderly and people with chronic develop the disease most often but this does not exclude ordinary individuals developing them.
- Intestinal polyps are noncancerous tumors of the GI tract, occurring mostly in people older than 40 years. A small proportion of these polyps may transform into Colonic polyps may bleed rapidly, or they may bleed slowly and go undetected.
- Haemorrhoids and fissures: are swellings of veins in and around your rectum. Repeated stretching from straining at stool causes them to bleed. Bleeding from hemorrhoids is usually mild, intermittent, and bright red. Massive bleeding is rare. Anal fissures, or tears in the anal wall, also may trigger small amounts of bright red bleeding from the anus. Forceful straining during passage of hard stool usually causes such tears, which can be very painful.
Picture 1 Sengstaken-Blakemore tube is inserted in the oesophagus and inflated to apply pressure on the bleeding varicose veins.
