IRCT20190703044084N2 IRCT 2020-04-20 Zanjan University of Medical Sciences ٍٍEffect of ondansetron in treatment of irritable bowel syndrome (IBS) The effect of ondansetron in the treatment of patients with diarrhea dominant irritable bowel syndrome (IBS) 2019-06-27 anticipated 100 Complete https://irct.ir/trial/41616 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: In this study, 100 patients with irritable bowel syndrome will be randomly studied in two groups, each including 50. Randomization in the mentioned groups will be conducted according to permuted block randomization based on quaternary blocks, Blinding description: This is a double-blind and placebo-controlled study. Placebo will be provided similar to androsterone in terms of taste, flavor and color, by the School of Pharmacy. The content of Placebo is Avicel. Medicines will be delivered to patients by a third person (a health care provider) who is not directly involved in the research. 3 Irritable Bowel Syndrome with diarrhea. Intervention 1: Intervention group: 50 patients treated by Imipramine (made by Abidi Pharma Compony) daily 25 mg and ondansetron (made by Abidi Pharma Compony) 4mg 3 times per day for up to 2 months. Intervention 2: Control group: 50 patients treated by Imipramine (made by Abidi Pharma Compony) daily 25 mg and placebo (containing Avicel and made by the School of Pharmacy) 4mg 3 times per day for up to 2 months. No - There is not a plan to make this available Justification or reason for not sharing IPD is No more information.