How much should i worry about traveler's diarrhea?

Depends location: Travelers diarrhea (td), a bacterial diarrheal infection is common in some locations and not in others. Td is common in countries where refrigeration and/or cooking fuel are in short supply. Check the cdc website and with your travel medicine specialist to determine risk at your destination. Learn to prevent it by washing your hands, eating cooked food served hot, and bottled or filtered water.

Plan, don't worry: Travelers diarrhea is a common (~30-50%) ailment in those visiting destinations with poor infrastructure (and hence increased risk of fecally contaminated food & water). The old adage "boil it, peel it, cook it, or forget it" only helps a little. Best is eat smart, and travel with self treatment (otc Imodium and rx antibiotic depending on destination: cipro, (ciprofloxacin) azithro, rifaximin) & hydration.