Medicine Name: Rifaxigyl-M Tablet. Composition: Rifaximin (200mg) + Metronidazole (400mg). Side Effects: Nausea Vomiting Diarrhea Stomach pain Constipation Dryness in mouth Flatulence Fever Headache Metallic taste Dizziness Abdominal distension Tenesmus increased urge to pass stools Bowel incontinence.