Rifaximin was initially developed for the treatment of bacteria-related diarrhea, but appreciation of its potentially broader use has increased as understanding of the importance of enteric bacteria in many organic and functional gastrointestinal diseases has advanced. This article reviews data that have been presented at medical meetings or published in medical journals since the publication of a 2006 rifaximin review in this journal. The data presented expand previous research, suggesting that rifaximin may be considered as monotherapy or combination therapy for a variety of enteric conditions, including Clostridium difficile-associated diarrhea, cryptosporidial diarrhea, Helicobacter pylori-associated gastritis, inflammatory bowel disease, pouchitis, diverticular disease, hepatic encephalopathy, small intestinal bacterial overgrowth, and irritable bowel syndrome. Although most of the new data come from small, uncontrolled studies, results are encouraging. Together, these studies suggest the efficacy of rifaximin and provide a foundation for further research that will help to better define the potential benefits of rifaximin in gastroenterology and hepatology.