The runs. The trots. Call it what you will -- diarrhea's a drag. Common travel wisdom is to let it run its course; plugging up the source keps the bad bacteria in. If you've paid a boatload for a day tour or a concert ticket, though, you've probably reached for remedies. Could prevention (other than not drinking the water, not eating the food and engaging in general gustatory boredom) be on the horizon?

I read a story from a student traveler not long ago regarding a Guatemala homestay -- the student mentioned incidentally that she was participating in a traveler's diarrhea prevention study and taking some mysterious stuff purported to be a possible diarrhea vaccine, shipped to her by Johns Hopkins. Having guzzled the Pepto in Central America myself, my curiousity was piqued. Today, USA Today reports that 1,406 U.S. students took the vaccine or a placebo before leaving for Guatemala or Mexico as part of the study.

The results are in -- 84% of the students who "responded" to the vaccine (meaning their bodies liked it) found it effectively blocked severe diarrhea, according to USA Today, and the vaccine stopped 63% of mild cases. It works as an immune system stimulator; your body, should it decide to "respond" to the vaccine, will attack foreign germ invaders storming the gates before the klaxon horns even sound.

(I have some questions: for instance, how did the participants know if a given case of diarrhea was going to be "severe" and the vaccine subsequently blocked it? The gut rumblings heralding the runs' arrival are unmistakeable, but I don't know that one can judge in advance whether the episode will be a brief bummer or a three day crippler.)

The traveler's diarrhea vaccine is not yet available as it's still being refined and perfected; stay tuned for updates.

Related topics:

• About Diarrhea
  
• CDC's Yellow Book - Health Information for International Travel