Gender and Differences in Diagnosis and Management of Veterans With IBS: A Retrospective Cohort Study Within a VA Health Care System

Introduction: Irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction with a heightened prevalence in Veterans (35%), compared to the general population (13%). Little is known about the current diagnostic and management strategies of Veterans with IBS within the Veteran Affairs (VA) health care system. Through a retrospective cohort study, we examined the relationship between clinical practices and Veteran gender and IBS subtype at a VA medical center. Methods: Veterans were selected if they had a new IBS diagnostic code entered in their chart for at least 2 clinic visits separated by a period of ≥ 6 months. They were further classified by gender and subtype; IBS-C, IBS-D, IBS-M, and IBS-Other. Via chart review, testing and recommendations were recorded with the standard of care being the American College of Gastroenterology IBS clinical guidelines. Accuracy was validated with a 10% check and statistical analysis for categorical variables (Chi-squared test) and continuous variables (Student’s T-test or Kruskal Wallis) was done. Results: Chart review of 136 eligible Veterans (32 female) with IBS was done. Subtype breakdown was IBS-C (14), IBS-D (60), IBS-M (22), and IBS-O (40). Avoiding antispasmodics was observed more often in females than males (84.4% vs 67.3%, P=0.075). Providers were less likely to recommend probiotics for IBS-C compared to IBS-D, IBS-M, and IBS-O (21.4% vs 50.0%, 50.0%, 52.5%, respectively) and less likely for females than males (37.5% vs 51.0%, P=0.266). The likelihood of recommending fiber was relatively similar for IBS-C, IBS-D, IBS-M, and IBS-O (42.9%, 46.7%, 54.5% and 45.0%, respectively). Fiber was recommended to females and males at essentially equal rates (46.9% vs 47.1%, P=1.00). A low FODMAP diet was more likely to be utilized in patients with IBS-D and IBS-M (20.0% and 18.2%) than with IBS-C and IBS-O (7.1% and 7.5%), and more likely to be recommended to females than males (21.9% vs 12.5%, P=0.190) (Table 1). Conclusion: Diagnostic and management strategies of Veterans with IBS were analyzed based on IBS subtype and gender. Fiber was not recommended in the majority of patients, but nearly twice as likely to be recommended to females than males. Other gender-based differences were appreciated, namely with respect to medications for IBS-D and dietary recommendations for IBS-C. Further research is warranted to understand healthcare utilization for Veterans of all genders and IBS subtypes. Table 1. - Diagnosis and management utilization among eligible cohort study subjects by IBS-subtype and gender IBS-C IBS-D IBS-M IBS-Other Guideline Followed F (N=8) M (N=6) P-value F (N=10) M (N=50) P-value F (N=6) M (N=16) P-value F (N=8) M (N=32) P-value IBS Generic Colonoscopy 6 (75%) 6 (100%) 0.47 10 (100%) 40 (80%) 0.19 5 (83%) 14 (88%) 1.00 8 (100%) 24 (75%) 0.17 Enteric Pathogen Stool Testing 7 (88%) 6 (100%) 1.00 6 (60%) 39 (78%) 0.25 6 (100%) 10 (63%) 0.13 6 (75%) 31 (97%) 0.096 Food Allergy Testing 8 (100%) 6 (100%) N/A 10 (100%) 50 (100%) N/A 6 (100%) 15 (94%) 1.00 8 (100%) 32 (100%) 0 Fiber 3 (38%) 3 (50%) 1.00 6 (60%) 22 (44%) 0.49 4 (67%) 8 (50%) 0.65 2 (25%) 16 (50%) 0.26 TCA 0 (0%) 3 (50%) .06 4 (40%) 15 (30%) 0.71 3 (50%) 3 (19%) 0.28 0 (0%) 1 (3%) 1.00 TCA Contraindication 3 (30%) 13 (26%) 1.00 3 (50%) 3 (19%) 0.28 Antispasmodics 7 (88%) 2 (33%) 0.091 8 (80%) 32 (64%) 0.47 4 (67%) 11 (69%) 1.00 8 (100%) 25 (78%) 0.31 Peppermint oil 0 (0%) 0 (0%) N/A 0 (0%) 1 (2%) 1.00 0 (0%) 0 (0%) N/A 0 (0%) 0 (0%) 0 Probiotics 6 (75%) 5 (83%) 1.00 4 (44%) 26 (52%) 0.73 5 (83%) 6 (38%) 0.15 5 (63%) 14 (44%) 0.44 Low FODMAP diet 1 (17%) 0 (0%) 1.00 2 (20%) 10 (20%) 1.00 4 (67%) 0 (0%) 0.002 0 (0%) 3 (9%) 1.00 IBS-C Specific Guanylate cyclase 6 (75%) 0 (0%) 0.01 Chloride channel activators 2 (25%) 0 (0%) 0.47 Tegaserod 5 (63%) 0 (0%) < 0.001 Tegaserod N/A 0 (0%) 6 (100%) N/A Polyethylene glycol 5 (63%) 4 (67%) 1.00 IBS-D Specific CeD Testing 3 (30%) 14 (29%) 1.00 3 (50%) 3 (19%) 0.28 Fecal Calprotectin 2 (20%) 7 (14%) 0.64 0 (0%) 2 (13%) 1.00 CRP 0 (0%) 7 (14%) 0.59 1 (17%) 1 (6%) 0.48 Rifaximin 0 (0%) 5 (10%) 0.58 0 (0%) 2 (13%) 1.00 Opioids 0 (0%) 0 (0%) N/A 0 (0%) 1 (6%) 1.00 Alosetron 9 (90%) 50 (100%) 0.17 5 (83%) 16 (100%) 0.27 Bile acid sequestrants 9 (90%) 47 (96%) 0.43 6 (100%) 15 (94%) 1.00 F: female, M: male, FODMAP: fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, TCA: tricyclic antidepressant, CeD: celiac disease, CRP: c-reactive protein.