If you are not basing your dinner on someone’s recommendations, rely on your common sense. Patronise restaurants that look busy in Saigon. Pay attention to cleanliness - are the tables you’re eating at clean? If you’re eating street food, consider the sanitation situation of the vendor’s cart and how they prepare the food. Try to eat freshly-cooked food. Bear in mind that dirty floors are the norm at street restaurants since it is the custom to leave refuse beneath the table to be swept up later on.
When eating seafood, go to restaurants that allow you to choose from a live aquarium and, if possible, places that prepare the food in front of you. If your stomach is wobbly, avoid eating peeled fruit or vegetables. Stay clear of shellfish, buffets, and communal bowls of finger foods including peanuts and popcorn. Eat in places where cooks (if you can see them) are wearing plastic gloves.
There are also a number of things you can do yourself to avoid that famous traveller’s diarrhea. One trick is to wash your hands before eating. Many restaurants will include a wet towel – usually chargeable – in the table setting. Do also consider what you eat. According to the Vietnamese and local Chinese, certain food should be eaten with other foods to create a harmonisation between Yin and Yang (warming and cooling to the body), unless you are fine risking ‘imbalances’. For example, try uncooked fish with a lot of ginger and a little bit of alcohol – the ‘natural medicines’ which help to ‘warm the stomach’ (làm ấm bụng) and avoid diarrhea.
A lot of the times, it’s the water that gives you a bad stomach. Remember that water from the tap is not potable, so do not drink water directly from it. Be mindful of the ice in your drink when eating out as well, and if possible, purchase distilled or purified water on a bottle just to be safe.
For information on food poisoning go to How NOT to Get Food Poisoning While Travelling