Gastroenteritis may be due to many agents, infectious or non infections. Most cases of infections diarrhea are selflimited--e.g. food born intoxications with 1 to 2 days duration or infections with enteropathogenic E. coli, Salmonella spp., Vibrio parahaemolyticus or rota virus. Even the majority of shigellosis, salmonella-gastroenteritis and infections with Campylobacter fetus cease without treatment within 4 days. Fever and diarrhea persisting for more than 4 days justify the use of antibiotics, favourably trimethoprim and quinolones. Fluid and electrolyte replacement is the mainstay of treatment. Antimotility agents worsen some forms of diarrhea (especially these due to enteroinvasic bacteria) by retarding the natural purgative effect of diarrhea.