Abnormally fast passage of waste material through the large intestine, resulting in frequent defecation with loose feces and sometimes cramps. Causes range widely and can include cholera, dysentery, highly seasoned foods or high alcohol intake, poisons (including food poisoning), drug side effects, and Graves' disease. Mild cases of diarrhea are treated with bismuth subsalicylate (trade name Pepto-Bismol); extreme cases are treated with fluid and electrolyte replacement while the underlying disease passes. Traveler's diarrhea affects up to half of people who travel to developing countries. Its prevention includes taking bismuth subsalicylate tablets, drinking only bottled or canned beverages, and eating only peeled fruits, canned products, and restaurant food that is well-cooked. Severe cases require antibiotics. In cases of severe malnutrition, diarrhea is potentially lethal, and it is responsible for hundreds of thousands of deaths annually in underdeveloped countries.