Rifaximin, sold under the trade name Xifaxan among others, is an antibiotic used to treat traveler's diarrhea, irritable bowel syndrome, and hepatic encephalopathy. It has poor absorption when taken by mouth. It is based on rifamycin. Rifaximin was approved for medical use in the United States in 2004. In the United States it costs 62.13 USD per day for 1100 mg of rifaximin as of January 2017. In Russia as of 2016 a similar dose costs 231.25 RUB.