Don't drink the water. I'm not kidding.
I'm sure you're a seasoned world traveller, etc, and I'm not trying to teach my granny to suck eggs, but you should take care to avoid the local water, don't take ice in your drinks and don't eat fruit that's been washed with local water. Live on bottled water.
If you decide to treat this advice in a devil-may-care fashion, I guarantee you will incur a severe dose of the runny bum-bum that will make your return journey a nightmare.
Have a LOVELY holiday.