digestive systemThe digestive tract is a series of joined and coiled hollow tubes that stretch from the mouth to the anus. Digestive diseases range from the occasional upset stomach to the more life-threatening colon cancer and encompass disorders of the gastrointestinal tract, the liver, the gallbladder, and the pancreas. A digestive disease may be acute and self-limiting, chronic and debilitating, or sudden and devastating.

What Causes a Digestive Disease?
The cause and natural history of many digestive diseases remain unknown, but a digestive disease may develop congenitally or from multiple factors such as stress, fatigue, diet, or smoking. Abusing alcohol imposes the greatest risk for digestive diseases, particularly increasing the risk of esophageal, colorectal, and liver cancers. Depending on the diagnosis, treatment options include prescription and non-prescription medications, surgery, watchful waiting, dietary changes, exercise, chemotherapy, and home remedies such as castor oil.

Who Develops a Digestive Disease?
Each year 62 million Americans are diagnosed with a digestive disorder. The incidence and prevalence of most digestive diseases increase with age. Notable exceptions are intestinal infections such as gastroenteritis and appendicitis, which peak among infants and children. Other exceptions include hemorrhoids, inflammatory bowel disease, and chronic liver disease, which occur more commonly among young and middle-aged adults. Women are more likely than men to report a digestive condition, particularly non-ulcer dyspepsia and irritable bowel syndrome (IBS). Whether women truly experience more troubles with their digestive systems than men is difficult to determine, but since women visit doctors more often than men, they have a greater opportunity to alert their doctors to their digestive problems.

How are Digestive Diseases Diagnosed?
Most digestive diseases are very complex, with subtle symptoms. Because of this, patients may undergo extensive and expensive diagnostic tests. Reaching a diagnosis requires a thorough and accurate medical history and physical examination. Once complete, a doctor may recommend laboratory tests, which may include a blood test, an upper or lower GI series, an ultrasound, and endoscopic examinations of the colon, esophagus, stomach, or small intestine. For more complicated cases, a doctor may order more sophisticated tests such as a CAT (computerized axial tomography) scan or MRI.

Economic Impact and Scope of Digestive Diseases
Digestive diseases cost nearly $107 billion in direct health care expenditures in 1992. Digestive diseases result in nearly 200 million sick days, 50 million visits to physicians, 16.9 million days lost from school, 10 million hospitalizations, and nearly 200,000 deaths per year. The most costly digestive diseases are gastrointestinal disorders such as diarrheal infections ($4.7 billion); gallbladder disease ($4.5 billion); colorectal cancer ($4.5 billion); liver disease ($3.2 billion); and peptic ulcer disease ($2.5 billion). Cancers of the digestive tract,which includes the colon, the gallbladder, and the stomach, are responsible for 117,000 deaths yearly. Non-cancerous digestive diseases cause 74,000 deaths a year, with 36 percent caused by chronic liver disease and cirrhosis. Of the 440 million acute non-cancerous medical conditions reported in the United States annually, more than 22 million are for acute digestive conditions, with 11 million from gastroenteritis and 6 million from indigestion, nausea, and vomiting. Digestive diseases have an enormous impact on health and the health-care system in the United States. New technologies and new drugs have revolutionized the understanding and treatment of peptic ulcer disease and Gastroesophageal Reflux Disease. Successful outcomes of future research will hopefully continue to reduce the economic and health care costs related to diagnosing and treating digestive diseases.

Research in Digestive Diseases
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) was established by Congress in 1950 as one of the Institutes of the National Institutes of Health (NIH). The mission of the NIH is to direct and support biomedical research that will lead to better human health. The NIDDK conducts and funds a range of research in digestive diseases and nutrition-related diseases, many of them chronic. Much of NIDDK's research in digestive diseases is conducted through the Silvio O. Conte Digestive Disease Centers Program, which began in the mid-1970's with the funding of two centers: the University of California, San Francisco and the Albert Einstein University, New York. Since then, the program has grown to 12 Digestive Disease Centers conducting basic and clinical research in digestive, hepatic, and pancreatic disorders. The diseases and conditions discussed in this overview are covered in greater detail by fact sheets and information packets. The statistics reported in this fact sheet come from Digestive Diseases in the United States: Epidemiology and Impact, edited by James Everhart, M.D., MPH., NIH Publication No. 94-1447. For copies of fact sheets, information packets,or the Digestive Diseases in the U.S., you may contact the National Digestive Diseases Information Clearinghouse (NDDIC), 2 Information Way, Bethesda, MD 20892-3570.