Rifaximin 550mg tablets are an antibiotic used to treat certain bacterial infections in the intestines, such as traveler’s diarrhea caused by E. coli, and irritable bowel syndrome with diarrhea (IBS-D). It is also used to reduce the risk of hepatic encephalopathy in people with liver disease. Rifaximin works by stopping the growth of bacteria in the intestines, which helps relieve symptoms like diarrhea and stomach pain. This medication is typically taken as prescribed by your doctor, with or without food. Common side effects may include nausea, gas, and headache. Since Rifaximin targets specific bacteria in the gut, it’s important to follow your doctor’s instructions and complete the full course of treatment for the best results.