Co-occurrence of Voiding Symptoms and Flatal Incontinence in Axial Spondyloarthritis: A Cross-Sectional Study.

backgroundAxial spondyloarthritis (axSpA) is a chronic inflammatory disease of the sacroiliac joints and spine whose burden extends beyond the musculoskeletal system. Lower urinary tract symptoms are increasingly recognised in these patients, whereas anorectal symptoms have received almost no attention. Because the lower urinary tract and the anorectal continence mechanism share pelvic floor musculature and sacral neural regulation, symptoms of these two systems might be expected to co-occur, yet this has not been examined in axSpA. Anxiety and depression are also common in this population and are recognised correlates of pelvic floor symptoms in other patient groups. These considerations provided the rationale for the present study.

objectivesThis study had two objectives: first, to determine whether voiding symptoms and flatal incontinence co-occur in patients with axSpA; and second, to identify the clinical and psychological factors independently associated with flatal incontinence.

methodsIn this cross-sectional study, 137 consecutive adult patients fulfilling the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axSpA and attending two outpatient clinics between January and December 2023 were enrolled. Flatal incontinence (involuntary leakage of gas) and voiding symptoms were ascertained by structured symptom inquiry using International Continence Society (ICS) symptom definitions. Disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)), functional status (Bath Ankylosing Spondylitis Functional Index (BASFI)), psychological status (Hospital Anxiety and Depression Scale (HADS)), and inflammatory markers (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) were recorded. For the first objective, the association between any voiding symptom and flatal incontinence was assessed with the chi-square test, with the unadjusted odds ratio (OR) derived from the corresponding contingency table. For the second objective, patients were categorised by flatal incontinence status and multivariable binary logistic regression was performed.

resultsFlatal incontinence was reported by 54 of 137 patients (39.4%), and at least one voiding symptom by 67 of 137 patients (48.9%). Flatal incontinence was significantly more frequent among patients with voiding symptoms than among those without (41/67, 61.2% vs 13/70, 18.6%; unadjusted OR 6.91, 95% confidence interval (CI) 3.18-15.04; P < 0.001). Patients with flatal incontinence had higher BASDAI (4.84 ± 1.93 vs 3.89 ± 2.01; P = 0.007), HADS-anxiety (8.72 ± 4.06 vs 6.29 ± 3.47; P < 0.001), and HADS-depression scores (7.30 ± 3.28 vs 5.53 ± 3.88; P = 0.007), whereas ESR and CRP did not differ between groups. In multivariable analysis, only anxiety remained independently associated with flatal incontinence (adjusted OR 1.16 per HADS-anxiety point, 95% CI 1.034-1.301; P = 0.012).

conclusionsVoiding symptoms and flatal incontinence frequently co-occurred in this axSpA cohort, and anxiety was independently associated with flatal incontinence. These hypothesis-generating findings raise the possibility of a broader sacropelvic symptom cluster in axSpA extending beyond the sacroiliac joints. Given the cross-sectional design and the absence of a control group, no causal or mediating role of psychological distress can be inferred.