Urinary incontinence (UI) affects both sexes but exhibits distinct patterns by gender. Understanding sex-specific differences and associated clinical factors is essential for tailored management approaches. We aimed to examine sex differences in UI prevalence, subtypes, and associated clinical correlates, including gastrointestinal symptoms and quality of life impact, in the general population of northwest Iran.

This cross-sectional study included 1,865 participants (49.8% male, 50.2% female; mean age 36.7 years) from three northwestern provinces. Validated Persian questionnaires (ICIQ-OAB, ICIQ-FLUTS, ICIQ-MLUTS, PFDI) assessed UI subtypes, gastrointestinal symptoms, and quality of life impact. Chi-square tests and independent t-tests were used for analysis (p < 0.05 significant).

UI was significantly more common in women (18.7%) than men (3.1%, p < 0.001). SUI was the predominant subtype in women (17.7%), while UUI showed no sex difference (women: 3.6%, men: 2.8%, p = 0.359). Women with UI reported significantly higher rates of gastrointestinal symptoms, particularly diarrhea (p < 0.001), compared to women without UI. A significant association was found between UI and FI co-occurrence in women (2.3%, p < 0.001). Urgency UI showed the strongest association with FI co-occurrence (9.7%), followed by MUI (12.0%) and SUI (2.4%). Quality of life impact, though mild in most participants, was significantly worse in those with UI, particularly those with co-occurring FI.

The findings highlight a clear sex disparity in urinary incontinence, with a markedly higher burden in women driven predominantly by stress urinary incontinence, likely reflecting anatomical and pelvic floor differences. The similar prevalence of urgency urinary incontinence between sexes suggests that storage dysfunction mechanisms may be less sex-dependent. The strong association between UI, particularly urgency and mixed subtypes, and fecal incontinence, along with the link to gastrointestinal symptoms such as diarrhea, supports the concept of shared pelvic floor and neuromuscular pathophysiology. Clinically, these results emphasize the need for a comprehensive, integrated evaluation of urinary and bowel symptoms, especially in women, and reinforce the importance of sex-specific and multidisciplinary management strategies to address the broader spectrum of pelvic floor dysfunction.

Significant sex differences exist in UI prevalence and subtype distribution, with SUI predominating in women. The association between UI and gastrointestinal symptoms, particularly diarrhea, and the co-occurrence with FI, suggest shared pathophysiological mechanisms. These findings support integrated assessment of pelvic floor disorders and consideration of sex-specific clinical approaches.