Comparative Efficacy and Safety of Fenoverine

Inclusion Criteria: * 18 years of age or older and 60 years of age or younger * Diagnosed as irritable bowel syndrome using Rome III Criteria * Female subjects of child-bearing potential are confirmed to have a negative urine beta-hCG test within 7 days prior to administration of initial dose of investigational products. * Female subjects of child-bearing potential must agree to use contraceptive measures during study period. Exclusion Criteria: * Known allergy or hypersensitivity to investigational products or components of the formulation * Past or current diagnosis of chronic liver disease (e.g., liver cirrhosis, acute hepatitis, alcoholic hepatitis, chronic alcohol abuse and HCC) * Past or current diagnosis of Myopathy * Subject with serious renal disease * Known medical condition assessed by investigators as inappropriate for the study * Continuous use of NSAIDS, analgesics, steroids, or other immunosuppressants. * Continuous use of HMG-CoA reductase inhibitors or fibrates to lower blood lipid level * Pregnant, lactating, or planning to be pregnant women * Evidence of abuse of drugs or alcohol within 6 months prior to screening * Participation in other clinical trials within 3 months prior to enrollment or elapse of less than 5 half lives of previous investigational product after last dose of it. * Unable to submit informed consent or comply with the requirements of the study