Avoiding Montezuma's Revenge

Due to the poor quality of the water in third world countries such as Mexico or Cambodia one must be very careful to avoid contracting severe travelers diarrhea also known as Montezuma's Revenge.  While the obvious sources of contamination such as drinking tap water at a restaurant should be avoided, it is also very important to make sure that you do not have any drinks that have ice or crushed ice in them.  This even goes for alcoholic drinks such as margaritas, don't think that just because there is some tequila in the frozen margaritas that it will stop you from becoming very ill.  Because of this it is important that you make sure that you rise off your toothbrush with bottled water and don't accidentally let it touch tap water accidentally.  Also you need to be careful when eating fruit, in most cases fruit that has a peel to it such as oranges is safe but with other fruit, like apples you need to make sure that you wash it with bottled water so as to remove the pathogens that might be on that surface layer.  In the end it isn't really that difficult to keep from getting sick, all you have to do is make sure you stay with sealed bottled drinks.  This is one instance where the factory seal is vital because I have seen locals selling bottles of water that they washed off and refilled from the tap themselves.  I have seen this done more with glass instead of plastic bottles but still it is good to make sure you keep an eye out to keep from getting sick.