It is used to treat diarrhea caused by the common bacteria known as E. coli ("traveler's diarrhea").

Nimixa Tablets 550mg 10's
Nausea, vomiting,constipation, diarrhea, bloating
It is contraindicated in patients with known hypersensitivity to the drug.
Before taking rifaximin, tell your doctor or pharmacist if you are allergic to it; or to other rifamycins (rifampin, rifabutin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Tell your doctor right away if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool. Do not use anti-diarrhea products or narcotic pain medications if you have any of these symptoms because these products may make them worse.
Before using this medication, tell your doctor or pharmacist your medical history.
Rifaximin may cause live bacterial vaccines (such as typhoid vaccine) to not work as well. Do not have any immunizations/vaccinations while using this medication unless your doctor tells you to.
Please consult your doctor when taking this medicine if you are pregnant.
Most antibiotics are unlikely to affect hormonal birth control such as pills, patch, or ring, a few antibiotics (such as rifampin, rifabutin) can decrease their effectiveness. This could result in pregnancy.