Effects of Demographic Factors, Body Mass Index, Alcohol Drinking and Smoking Habits on Irritable Bowel Syndrome: A Case Control Study

BACKGROUND Irritable Bowel Syndrome (IBS) is a common functional gastrointestinal disorder. AIMS To identify demographic factors in patients with IBS. SUBJECTS AND METHODS One-hundred and fifty three IBS patients seen at Taleghani Hospital Gastroenterology Clinic and met the Rome III criteria and 163 peoples who did not meet IBS criteria were consecutively enrolled. Both groups were asked to complete a self-rating questionnaire containing information, which included questions about age, sex, monthly income, education level, marital status, height, weight, alcohol drinking and smoking habits. Student's t-test, Pearson's Chi-square and logistic regression were used to statistical analysis. RESULTS The mean (SD) age for IBS patients 36.3 (13.5) years and 33.1 (9.9) years in non-IBS group (P < 0.001). Frequency of IBS defined by Rome III criteria was higher in females and younger individuals. Univariate analysis showed that IBS in males was associated with a lower monthly income and educational level and in females younger age, single, lower monthly income and educational level, body mass index (BMI), and unemployment status. Multivariate logistic regression identified a low level of education in males (Odds ratio [OR] = 3.6, 95% Confidence interval [CI]: 1.4-9.6) and in females, lower education level (OR = 2.4, 95% CI: 1.1-5.2), lower BMI (OR = 0.94, 95% CI: 0.89-0.99), unemployed (OR = 0.31, 95% CI: 0.11-0.85) and smoking (OR = 6.2, 95% CI: 1.03-37.2). CONCLUSION We identified demographic factors in IBS patients. Being single and having a lower educational level, income, lower BMI and being unemployed were the most important factors associated with IBS, particularly in females.