Most gastrointestinal bleeding arises from benign conditions.
Blood in your stool can take several forms. Hematochezia, the passing of bright red blood from your rectum, is one of the most frightening manifestations of gastrointestinal bleeding. Melena is a tarry black stool resulting from the action of digestive enzymes on blood as it passes through your GI tract. Occult blood, which arises from slow bleeding within your intestine, cannot be seen with the naked eye but can be detected with special tests. All rectal bleeding -- whether or not it is associated with abdominal pain -- warrants a medical evaluation. If you suddenly lose large amounts of blood, see your doctor immediately.
According to a 2012 review in the вЂњWorld Journal of Gastroenterology,вЂќ bleeding from the upper gastrointestinal tract is a more common cause of sudden, significant blood loss than is lower GI bleeding. Peptic ulcers and gastritis -- inflammation of the stomach lining -- are the most common causes of acute upper GI bleeding in all age groups. In young people, the most common cause of lower GI bleeding is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. In people over the age of 50, the most common cause of lower GI bleeding is diverticulosis, which is characterized by small pouches protruding from the wall of the colon.
In most cases, chronic bleeding from the upper GI tract results from gastritis, ulcers or inflammation in the lower esophagus, which usually stems from acid reflux disease. Stomach or esophageal cancers are uncommon causes of chronic upper GI bleeding. Hemorrhoids, colon polyps, ulcerative colitis, colon cancer and diverticulosis are the most common causes of chronic blood loss from the lower GI tract. Bleeding occasionally arises from arteriovenous malformations, which are abnormal, fragile blood vessels that can occur throughout the GI tract.
Pain Location Provides a Clue
Many of the conditions that cause GI bleeding do not cause pain. Diverticulosis, colon polyps and arteriovenous malformations tend to cause painless bleeding. Many cancers are painless, at least until they are quite large or advanced. In contrast, peptic ulcers, gastritis and inflammatory bowel diseases are typically painful, at least intermittently. Diverticulitis -- the inflammatory form of diverticulosis -- and esophageal inflammation can cause pain, too. If you have sharp pains in the pit of your stomach, you may have an ulcer, gastritis or esophageal inflammation. Bleeding from these conditions usually causes melena or occult blood. Sharp pains in your lower abdomen could be caused by inflammatory bowel disease -- ulcerative colitis is more likely to cause bleeding than Crohn's disease -- or diverticulitis. Colon cancer is a less likely possibility. Lower GI bleeding usually causes hematochezia or, if it is quite slow, occult blood.
Although rectal bleeding usually results from conditions that are not life threatening, your doctor may want to rule out cancer, inflammatory bowel disease, ulcers and other potentially serious causes of your pain and bleeding. For people with GI bleeding but no other symptoms, the American Gastroenterological Association recommends both upper and lower endoscopy, which involves passing a flexible scope into your upper and lower intestine. These examinations permit direct visualization of your esophagus, stomach, upper small intestine and colon. The evaluation may be tailored to the location of your pain; the nature of your rectal bleeding; any additional symptoms you may have, such as fever or joint pain; and other risk factors for GI bleeding, such as regular use of aspirin or other antiinflammatory medications. If your doctor chooses to proceed with either upper or lower endoscopy but cannot identify a source of bleeding, other tests, such as capsule endoscopy, may be ordered. This examination involves swallowing a tiny digital camera that can generate images as it passes through your intestine. Treatment for gastrointestinal bleeding is determined by the underlying cause.