John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
The causes of gastrointestinal (GI) bleeding are classified into upper or lower, depending on their location in the GI tract.
Upper GI bleeding
Peptic ulcer disease:Peptic ulcers are localized erosions of the mucosal lining of the digestive tract. Ulcers usually occur in the stomach or duodenum. Breakdown of the mucosal lining results in damage to blood vessels, causing bleeding.
Gastritis: General inflammation of the stomach lining, which can result in bleeding.
Gastritis also results from an inability of the gastric lining to protect itself from the acid it produces. NSAIDs (nonsteroidal anti-inflammatory drugs), steroids, alcohol, burns, and trauma can cause gastritis.
Esophageal varices: Swelling of the veins of the esophagus or stomach usually resulting from liver disease. Varices most commonly occur in
alcoholic liver cirrhosis. When varices bleed, the bleeding can be massive, catastrophic and occur without warning.
Mallory-Weiss tear: A tear in the esophageal or stomach lining, often as a result of
vomiting or retching. Mucosal 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.
Inflammation: 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
promote gastric ulcer formation. Helicobacter pyloriis a type of
bacteria that also promotes formation of ulcers.
Lower GI bleeding
One of the most common causes of lower GI bleeding. Small out-pockets, or diverticula, form in the wall of
the colon (large intestine), usually in a weakened area of the bowel wall.
The person may develop several pockets, which are more common in people who have constipation and strain
during a bowel movement.
Inflammatory bowel disease (IBD): Flares of inflammation from IBD often cause
mucousy stool that has blood mixed in it.
Infectious diarrhea: Some viruses or bacteria can cause damage to the
inner lining of the intestines, which can lead to bleeding.
Angiodysplasia: Along with diverticulosis, this is one of the most common causes of lower GI bleeding. Angiodysplasia is a malformation
of the blood vessels in the wall of the GI tract. These are most commonly in the large intestine and often bleed.
The elderly and people with
chronic kidney failure develop the disease most often.
Polyps: Intestinal polyps are noncancerous tumors of the GI tract, occurring mostly in people older than 40 years
of age. A small proportion of these polyps may transform into cancer.
Colon polyps may bleed rapidly, or they may bleed slowly and go undetected.
Hemorrhoids and fissures: Hemorrhoids are swollen veins in and
around the anus. Repeated stretching from straining during bowel movements causes them to bleed. Bleeding from hemorrhoids is usually mild, intermittent, and bright red. 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
and may require surgery.