To Compare the Efficacy of Drugs in Combination for Treating Irritable Bowel Syndrome Associated With Diarrhea

The goal of this clinical trial is to compare the efficacy of four different drugs in combination for management of irritable bowel syndrome (IBS)-associated diarrhea. The main question to answer is: * Is there a significant difference in effect of different drug combinations in management of irritable bowel syndrome with diarrhea? Participants will be divided into 3 treatment groups. * Each group will be given a combination of drugs for 2 weeks * At the end of study, efficacy of different drug combinations and their potential side effects will be compared between the treatment groups