IRCT20200928048862N1 IRCT 2020-10-16 Iran University of Medical Sciences The effect of duloxetine in quality of life and symptoms of patients with irritable bowel syndrome (IBS) The effect of duloxetine in quality of life and symptoms of patients with irritable bowel syndrome (IBS) 2018-10-27 anticipated 60 Complete https://irct.ir/trial/51415 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Simple randomization based on a table of random numbers into two groups of intervention and control, Blinding description: This study was a double blind study in which in this study both patients and evaluators were blind of the used drug. The drugs were delivered to the patients by another person in similar packages marked with a code. In the end, the researcher evaluated the patients without knowing the type of used drug. 1-2 Irritable Bowel Syndrome. Intervention 1: Intervention group: One 30 mg duloxetine capsule per day from Tadbir Kalay Jam Pharmaceutical Company, along with 135 mg Mebeverine tablets, twice at day for 12 weeks. Intervention 2: Control group: placebo in the form of capsules, similar to duloxetine at a dose of 30 mg per day with 135 mg drug Mebeverine for 12 weeks, from Tadbir Kalay Jam Pharmaceutical Company. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is Because of moral considerations