S1121 Role of Gender and Obesity on Irritable Bowel Syndrome Subtypes in a Veteran Population

Introduction: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that presents with chronic abdominal pain and abnormal bowel habits. Nearly 30% of United States veterans are affected by IBS, resulting in increased office visits and hospitalizations. Prior studies suggest that IBS subtypes may vary based on gender and body mass index (BMI). This study aims to evaluate the relationship between IBS subtypes and gender as well as obesity among veterans. Methods: We performed a retrospective chart review, including patients diagnosed with IBS who were seen in our gastroenterology clinic at an urban Veteran’s Affairs (VA) Hospital from October 2023 to October 2024. IBS diagnosis was made based on the Rome IV criteria. We excluded patients with inflammatory bowel disease, colorectal cancer, and constipation or diarrhea attributed to other etiologies. We excluded IBS-M patients as it is not clear if the symptoms are constipation or diarrhea predominant. All statistical analyses were performed using R (version 4.4.2). Fisher’s exact test was utilized to compare proportions given the smaller sample size of the data. Statistical analyses performed were 2-tailed, and a P value less than 0.05 was considered statistically significant. Results: Fifty-one patients with a diagnosis of IBS were seen from October 2023 to October 2024. Among those patients, 48 had a diagnosis of IBS-C or IBS-D. Of the 48 patients included, 60.4% were men and 39.4% were women. Men were found to be predominately diagnosed with IBS-D (58.3%), whereas women were predominately diagnosed with IBS-C (60%, P = 0.012). There was a trend towards a higher prevalence of obesity (BMI >30) among IBS-D versus IBS-C patients (61.5% vs 38.4%, P = 0.624), but this difference did not reach statistical significance. Conclusion: Our study found significant relationships between gender, obesity, and the distribution of IBS subtypes among veterans. We found that among veterans with IBS, men predominantly have a diarrhea-predominant phenotype, whereas women predominately have constipation. We also saw a trend towards a higher prevalence of obesity among IBS-D versus IBS-C patients. Several pathophysiological mechanisms have been thought to be linked to these differences, such as gender-specific hormones and inflammatory cytokines. Understanding this difference in gender predilection and its relationship with obesity may allow us to screen for IBS symptoms and provide more effective therapeutic options earlier in our veteran population.