My friends who are frequenters to Mexico told me about acidophilus pills. Same 'good bacteria' in yogurt, but you can take it in pill form, and its a lot more potent. The local health food store recommended taking it for several days before we go, to establish really strong colonies of the "good" bacteria and continue taking it each day in Mexico to fend off the 'bad.' Same basic theory as the Pepto, but probably slightly better for you overall, and no icky taste. We are going to try it. Also bought several holistic hangover cures..... planning on using those a lot too!