Among the nonantimicrobial agents that are available and useful for the prevention of traveler's diarrhea are bismuth subsalicylate-containing preparations, which can provide a rate of protection of up to 65% when taken 4 times daily. In one study, the probiotic Lactobacillus GG was found to provide 49% protection against traveler's diarrhea, but results with this agent and other probiotics have been highly variable and geographically inconsistent. Tannin albuminate plus ethacridine lactate provided 36% protection, but it is not widely available. Among the nonantimicrobial agents that are available and useful for the treatment of traveler's diarrhea are bismuth subsalicylate-containing preparations, which reduce the passage of loose stools by 16%-18%. The antisecretory and antimotility agent loperamide reduces the passage of loose stools by approximately 50% and has been especially useful, in combination with antimicrobial agents, in reducing the total duration of posttreatment diarrhea to a matter of hours.