This is common, due to changes in food preparation and new parasites that your body is not used to, unlike the locals.
The symptoms of diarrhea are abdominal cramps, vomiting, nausea, fever and loose stool. Keep hydrated, replenish your minerals, eat what you can, and if the symptoms persist for over 12 hours, visit a doctor as you may need antibiotics or other care.
Practice the following precautions:
* Tap water should not come into contact with your mouth - don't use it for anything, don't swallow any by accident, and drink from sealed bottles of water or the water provided by the hotel.Health Advisory: | CDC: Center of Disease Control and Prevention - Dominican Republic |