I am helping ds1 with his packing for his exciting trip travelling around Vietnam but have never been to that region of the world and have no idea what he should ideally put in his backpack for inevitable upset stomachs etc. Can any more seasoned MN travellers give me any suggestions (I don't want to weigh him down with a gazillion things to allay every fear I have but also want him to have whatever a sensible backpacker would take). Thanks!!