GASTROENTERITIS

acute infectious syndrome of the stomach lining and the intestines. It is characterized by diarrhea, vomiting, and abdominal cramps. Other symptoms can include nausea, fever, and chills. The severity of gastroenteritis varies from a sudden but transient attack of diarrhea to a life-threatening disease with severe dehydration. Numerous viruses, bacteria, and parasites can cause gastroenteritis, and the specific cause of the disease can be identified in only about two-thirds of cases. Microorganisms produce gastroenteritis by secreting toxins that stimulate excessive water and electrolyte loss, causing watery diarrhea; or by directly invading the walls of the gut, triggering an inflammatory response that destroys the balance between the digestive system's absorption of nutrients and the secretion of wastes. Among the forms of gastroenteritis besides the aforementioned are classic food poisoning, cholera, and traveler's diarrhea, which develops within a few days after traveling to a country or region that has unsanitary water or food. Traveler's diarrhea is caused by exposure to enterotoxin-producing strains of the common intestinal bacterium Escherichia coli. The treatment of gastroenteritis depends on the cause and the severity of symptoms and may include antibiotics or simply supportive care. Adults tend to have milder cases of the illness than do children and the very old, who run the risk of dehydration due to diarrhea and vomiting.