Since<unk>  can be caused by insufficient hygiene, contaminated water, and (possibly) increased susceptibility from vitamin deficiency, prevention methods should address these causes. Hygiene The risk of fecal-oral transmission of pathogens that cause diarrhea can be significantly reduced by good hygiene, including washing hands with soap and water after urination and defecation, and washing eating utensils with warm soapy water. Additionally a three-bowl system can be used for washing eating utensils. Treating water Water can be treated in the<unk>  through filtering, chemical disinfectants, a portable ultraviolet light device, pasteurizing or boiling. Factors in choice may include the number of people involved, space and weight considerations, the quality of available water, personal taste and preferences, and fuel availability. In a study of long-distance backpacking, it was found that water filters were used more consistently than chemical disinfectants. Inconsistent use of iodine or chlorine may be due to disagreeable taste, extended treatment time or treatment complexity due to water temperature and turbidity. Because methods based on halogens, such as iodine and chlorine, do not kill Cryptosporidium, and because filtration misses some viruses, the best protection may require a two-step process of either filtration or coagulation-flocculation, followed by halogenation. Boiling is effective in all situations. Iodine resins, if combined with microfiltration to remove resistant cysts, are also a viable single-step process, but may not be effective under all conditions. New one-step techniques using chlorine dioxide, ozone, and UV radiation may prove effective, but still require validation. Ultraviolet (UV) light for water disinfection is well established and widely used for large applications, like municipal water systems. Some hikers use small portable UV devices which meet the U.S. EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers, for example, the SteriPEN. Another approach to portable UV water purification is solar disinfection (also called sodis). Clear water is sterilized by putting it in a clear polyethylene (PET) bottle and leaving it in direct sunlight for 6 hours. Water risk avoidance Different types of water sources may have different levels of contamination: * More contamination may be in water that # likely could have passed through an area subject to heavy human or animal use # is cloudy, has surface foam, or has some other suspicious appearance. * Less contamination may be in water from # springs (provided the true source is not surface water a short distance above) # large streams (those entering from the side may have less contamination than those paralleling the trail) # fast-flowing streams # higher elevations # lakes with undisturbed sediments (10 days undisturbed water storage can result in 75–99% removal of coliform bacteria by settling to the bottom) # freshly melted snow # deep wells (provided they aren't subject to contamination from surface runoff) # regions where there was a heavy snow year when streams run full and long compared to dry years. Rain storms can either improve or worsen water quality. They can wash contaminants into water and stir up contaminated sediments with increasing flow, but can also dilute contaminants by adding large amounts of water. Unfortunately, there have not been any epidemiological studies to validate the above, except possibly for the case of spring water. Vitamins One study suggests that on very long trips in the<unk> , taking multivitamins may reduce the incidence of diarrhea.
Wilderness-acquired diarrhea
Antibiotic-associated diarrhea
Travelers' diarrhea
Factitious diarrhea
Porcine epidemic diarrhoea
Riga–Fede disease
Food protein-induced enterocolitis syndrome
Brainerd diarrhea