https://www.selleckchem.com/products/nu7026.html Background Irritable Bowel Syndrome (IBS) is one of the most commonly diagnosed gastrointestinal disorders, and its etiology is believed to be multifactorial. The role of smoking in the pathophysiology of IBS still remains inconclusive. Hence, we aim to investigate whether or not an association exists between smoking and IBS. Methods A cross-sectional study was conducted in a tertiary care hospital of Karachi. A sample size of 200 smokers and 200 non smokers was selected. A two-part self-reported questionnaire was administered to the participants and the diagnosis of IBS was based on the Rome III diagnostic criteria. All data were analyzed using the Statistical Package for the Social Sciences version 17. Statistical tests employed were Independent samples t-test, chi-square test, and binary logistic regression analysis to obtain Odds Ratio (OR) for various variables. A P-value less then 0.05 was considered statistically significant. Results Overall prevalence of IBS based on Rome III criteria was 9.5% (95% CI 9.45-9.60). Smoking was significantly found to be associated with IBS (P=0.002). Binary logistic regression analysis indicated that non-smokers were more likely to have IBS (Crude OR 3.00, 95% CI 1.23-7.30) than smokers, and females were more likely to have IBS (Crude OR 3.73, 95% CI 1.56-7.69) than males. Age, BMI, and food groups were not found to be significantly associated with IBS. Conclusion Our study concludes that IBS was more prevalent among non-smokers and amongst females. Further studies are required to firmly establish the role of smoking in IBS.Background Research ethics committees are comprised of policymakers, supervisors, and decision-makers and aim at increasing adherence to professional ethics standards in conducting health-related research. The existential philosophy of these committees is to preserve the patients' health, maintain and promote public trust in health care providers, protect the