Irritable bowel syndrome, a prevalent functional bowel disorder, significantly affects patients' everyday lives and imposes a substantial economic burden on society. However, treatments options for managing diarrhea-predominant irritable bowel syndrome are limited. Rifaximin along with metronidazole is proposed as a treatment option for irritable bowel syndrome with diarrhea. The aim of this study was to evaluate the efficacy and tolerability of a fixed dose combination of rifaximin and metronidazole in the management of irritable bowel syndrome with diarrhea. An open-label, non-comparative, non- randomized, multicentre trial was conducted in 25 subjects presenting with acute diarrheal episodes associated with irritable bowel syndrome. The study was approved by institutional research ethics committee and participants provided signed informed consent. Patients were given fixed dose combination tablet containing rifaximin 200mg and metronidazole 400mg twice daily for 5 days.