context: Traveler's diarrhea is an intestinal infection that occurs as a result of eating or drinking contaminated food or water. Food handlers who do not wash their hands after they use the bathroom can transmit the infection to people who consume the contaminated food. Areas where there is the highest risk of contracting traveler's diarrhea include the developing countries of Africa, the Middle East, Latin America, and Asia. The risk of infection varies depending on the type of exposure -- from a fairly low risk from eating hot, cooked foods and drinking factory-sealed beverages to a higher risk from eating raw vegetables and fruits and drinking tap water. The most common culprit is a bacteria called E.coli. The typical symptoms of traveler's diarrhea include: Abrupt onset of diarrhea Fever Nausea and vomiting Bloating Urgent need to have a bowel movement Malaise (weakness or discomfort) Explosive and painful gas Cramps Loss of appetite Traveler's diarrhea usually lasts from 3 to 7 days and is rarely life threatening. As with all diseases, it is best to consult a doctor rather than attempting to self-medicate for traveler's diarrhea. This is especially relevant for pregnant women and children. Pepto- Bismol (2 ounces four times daily or two tablets four times daily) decreases the diarrhea and shortens the duration of the illness. This medication also appears to be effective in preventing traveler's diarrhea, but it should not be taken for more than three weeks at a time. Side effects of Pepto- Bismol can include temporary blackening of tongue and stools, occasional nausea, constipation, and rarely, ringing in the ears. Do not take Pepto- Bismol if you have an aspirin allergy, renal insufficiency, gout, or if you are taking anticoagulants, probenecid ( Benemid, Probalan), or methotrexate ( Rheumatrex). The most important treatment requires the replacement of fluids and salts lost from diarrhea. This is best achieved by use of an oral rehydration solution such as the World Health Organization oral rehydration salts ( ORS) solution. ORS packets are available at stores or pharmacies in almost all developing countries. ORS is prepared by adding one packet to boiled or treated water. Packet instructions should be followed carefully to ensure that the salts are added to the correct volume of water. ORS solution should be consumed or discarded within 12 hours if stored at room temperature or within 24 hours if refrigerated. An antidiarrheal medication, such as Lomotil or Imodium, can decrease the number of diarrheal stools but can also cause complications for people with serious infections. These drugs should not be used by anyone with a high fever or blood in their stools. Antibiotics such as cirpofloxacin ( Cipro), norfloxacin ( Noroxin), rifamycin ( Amecolo), and sulfamethoxazole-trimethoprim ( Bactrim, Septra), and or may shorten the length of illness. The CDC does not recommend the use of most antibiotics to prevent traveler's diarrhea, with the exception of azithromycin ( Zithromax), because they can sometimes cause additional problems. Azithromycin is specificately used to treat traveler's diarrhea. Consult your doctor about taking these medications. It is important for an infected person to consult a doctor about treating diarrhea in children and infants, because some of the drugs mentioned above are not recommended for children. The greatest risk for children, especially infants, is dehydration. Again, the best treatment for dehydration is the ORS solution. Breastfed infants should continue nursing on demand. For bottle-fed infants, full-strength lactose-free or lactose-reduced formulas should be used. Be sure to mix the formula with boiled water that has cooled. Older children receiving semisolid or solid foods should continue to receive usual foods if they have diarrhea. Immediate medical attention is required if an infant with diarrhea develops signs of moderate to severe dehydration (including dry mouth, eyes, and skin), confusion; sunken eyes; and fever, bloody diarrhea, persistent vomiting, or fever higher than 102 F. Seek medical help for traveler's diarrhea if: Diarrhea is severe, bloody, or does not resolve within a few days Diarrhea is accompanied by fever and chills You are unable to keep fluids down to prevent dehydration In areas with poor sanitation, only the following beverages may be safe to drink: boiled water, hot beverages (such as coffee or tea) made with boiled water, canned or bottled carbonated beverages, beer, and wine. Avoid ice, as it may have been made from contaminated water. It is safer to drink from an unopened can or bottle than from a container that is not known to be clean and dry. Water on the surface of a beverage can or bottle may also be contaminated. Therefore, the area of a can or bottle that will touch the mouth should be wiped clean and dried. Where water may be contaminated, you should not brush your teeth with tap water. Boiling is the most reliable method to make water safe to drink. Bring water to a vigorous boil, then allow it to cool; do not add ice. At high altitudes, allow water to boil vigorously for a few minutes or use chemical disinfectants. Chemical disinfection can be achieved with either iodine or chlorine. Iodine usually provides greater disinfection. For disinfection with iodine, use either tincture of iodine or tetraglycine hydroperiodide tablets, such as Globaline or Potable- Aqua. These disinfectants can be found in sporting goods stores and pharmacies. Read and follow the manufacturer's instructions. If the water is cloudy, strain it through a clean cloth and double the number of disinfectant tablets added. If the water is very cold, either warm it or allow increased time for the disinfectant to work. Adding a pinch of salt or pouring water from one container to another will improve the taste. Portable water filters are not recommended due to lack of independently verified results of the filters' effectiveness. As a last resort, if no source of safe drinking water is available, tap water that is uncomfortably hot to the touch may be safer than cold tap water. However, many disease-causing organisms can survive the usual temperature reached by the hot water in overseas hotels and boiling or proper disinfection is still advised. Food should be selected with care. Foods you should avoid include: Salads Uncooked vegetables and fruit. If you peel fruit yourself, it is generally safe. Unpasteurized milk and dairy products Raw meat and shellfish Food that has been cooked and is still hot is usually safe. Some fish is not guaranteed to be safe, even when cooked, because of the presence of toxins in its flesh. Tropical reef fish, red snapper, amberjack, grouper, and sea bass can occasionally be toxic at unpredictable times if they are caught on tropical reefs rather than in the open ocean. The barracuda and puffer fish are often toxic and should generally not be eaten. Seafood from the islands of the West Indies and the tropical Pacific and Indian Oceans should be avoided, as it is more likely to contain toxins.