The digestive or gastrointestinal (GI) tract includes the esophagus, stomach, small intestine, large intestine or colon, rectum, and anus. Bleeding can come from one or more of these areas, that is, from a small area such as an ulcer on the lining of the stomach or from a large surface such as an inflammation of the colon. Bleeding can sometimes occur without the person noticing it. This type of bleeding is called occult or hidden. Fortunately, simple tests can detect occult blood in the stool.
The stomach is a frequent site of bleeding. Alcohol, aspirin, aspirin-containing medicines, and various other medicines (particularly those used for arthritis) can cause stomach ulcers or inflammation (gastritis). The stomach is often the site of ulcer disease. Acute or chronic ulcers may enlarge and erode through a blood vessel, causing bleeding. Also, patients suffering from burns, shock, head injuries, or cancer, or those who have undergone extensive surgery may develop stress ulcers. Bleeding can occur from benign tumors or cancer of the stomach, although these disorders usually do not cause massive bleeding.
The most common source of bleeding from the upper digestive tract is ulcers in the duodenum (the upper small intestine). Researchers now believe that these ulcers are caused by excess stomach acid and infection with Helicobacter pylori bacteria.
In the lower digestive tract, the large intestine and rectum are frequent sites of bleeding. Hemorrhoids are probably the most common cause of visible blood in the digestive tract, especially blood that appears bright red. Hemorrhoids are enlarged veins in the anal area that can rupture and produce bright red blood, which can show up in the toilet or on toilet paper. If red blood is seen, however, it is essential to exclude other causes of bleeding since the anal area may also be the site of cuts (fissures), inflammation, or tumors.
Benign growths or polyps of the colon are very common and are thought to be forerunners of cancer. These growths can cause either bright red blood or occult bleeding. Colorectal cancer is the second most frequent of all cancers in the United States and usually causes bleeding at some time.
Inflammation from various causes can produce extensive bleeding from the colon. Different intestinal infections can cause inflammation and bloody diarrhea. Ulcerative colitis can produce inflammation and extensive surface bleeding from tiny ulcerations. Crohn's disease of the large intestine can also produce spotty bleeding.
Diverticular disease caused by diverticula--outpouchings of the colon wall--can result in massive bleeding. Finally, as one gets older, abnormalities may develop in the blood vessels of the large intestine, which may result in recurrent bleeding.
If sudden massive bleeding occurs, a person may feel weak, dizzy, faint, short of breath, or have crampy abdominal pain or diarrhea. Shock may occur, with a rapid pulse, drop in blood pressure, and difficulty in producing urine. The patient may become very pale. If bleeding is slow and occurs over a long period of time, a gradual onset of fatigue, lethargy, shortness of breath, and pallor from the anemia will result. Anemia is a condition in which the blood's iron-rich substance, hemoglobin, is diminished.
The endoscope is a flexible instrument that can be inserted through the mouth or rectum. The instrument allows the doctor to see into the esophagus, stomach, duodenum (esophago-duodenoscopy), colon (colonoscopy), and rectum (sigmoidoscopy); to collect small samples of tissue (biopsies); to take photographs; and to stop the bleeding.
Small bowel endoscopy, or enteroscopy, is a new procedure using a long endoscope. This endoscope may be introduced during surgery to localize a source of bleeding in the small intestine.
Angiography is a technique that uses dye to highlight blood vessels. This procedure is most useful in situations when the patient is acutely bleeding such that dye leaks out of the blood vessel and identifies the site of bleeding. In selected situations, angiography allows injection of medicine into arteries that may stop the bleeding.
Radionuclide scanning is a noninvasive screening technique used for locating sites of acute bleeding, especially in the lower GI tract. This technique involves injection of small amounts of radioactive material. Then, a special camera produces pictures of organs, allowing the doctor to detect a bleeding site.
In addition, barium x-rays, angiography, and radionuclide scans can be used to locate sources of chronic occult bleeding. These techniques are especially useful when the small intestine is suspected as the site of bleeding since the small intestine may not be seen easily with endoscopy.
Active bleeding from the upper GI tract can often be controlled by injecting chemicals directly into a bleeding site with a needle introduced through the endoscope. A physician can also cauterize, or heat treat, a bleeding site and surrounding tissue with a heater probe or electrocoagulation device passed through the endoscope. Laser therapy, although effective, is no longer used regularly by many physicians because it is expensive and cumbersome.
Once bleeding is controlled, medicines are often prescribed to prevent recurrence of bleeding. Medical treatment of ulcers to ensure healing and maintenance therapy to prevent ulcer recurrence can also lessen the chance of recurrent bleeding. Studies are now under way to see if elimination of Helicobacter pylori affects the recurrence of ulcer bleeding.
Removal of polyps with an endoscope can control bleeding from colon polyps. Removal of hemorrhoids by banding or various heat or electrical devices is effective in patients who suffer hemorrhoidal bleeding on a recurrent basis. Endoscopic injection or cautery can be used to treat bleeding sites throughout the lower intestinal tract.
Endoscopic techniques do not always control bleeding. Sometimes angiography may be used. However, surgery is often needed to control active, severe, or recurrent bleeding when endoscopy is not successful.
Clayman, CB, ed. The American Medical Association Encyclopedia of Medicine. New York: Random House, 1989. General medical guide with sections on common disorders that cause digestive tract bleeding. Available in libraries and bookstores.
Larson, DE, Editor-in-chief. Mayo Clinic Family Health Book. New York: William Morrow and Company, Inc., 1990. General medical guide with sections on common disorders that cause digestive tract bleeding. Available in libraries and bookstores.
Marshall, JB. Bleeding esophagogastric varices: Ways to treat active episodes and prevent recurrence. Postgraduate Medicine 1991; 89(6): 147-50, 155-57.
Therapeutic Endoscopy and Bleeding Ulcers. National Institutes of Health. Consensus Development Conference Statement. 7(6): March 1989.
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