Interstitial cystitis/ bladder pain syndrome (IC/BPS) is a heterogeneous multifactorial disease and is highly associated with somatic symptoms. Pelvic floor muscle tenderness has also been complained of in a certain percentage of women with IC/BPS. This study explored the relationship between pelvic floor muscle tenderness, urinary biomarkers, and bladder condition in women with IC/BPS.

Patients with IC/BPS were prospectively enrolled, and a vaginal digital examination was performed. Numerical rating scales (NRS) were used to quantify the severity of pelvic floor muscle tenderness. The patients were assessed with demographics, IC symptom index (ICSI), IC problem index (ICPI), and Beck anxiety and depression inventory. The objective assessment items included computed tomography (CT) of the bladder, urodynamic parameters, maximum bladder capacity, glomerulation grade, urine inflammatory proteins, and oxidative stress biomarkers.

92 women with IC/BPS were evaluated, with pelvic floor muscle tenderness defined as the presence of at least one trigger point and an NRS score of ≥ 4. Patients with pelvic floor muscle tenderness exhibited significantly higher rates of dyspareunia (p = 0.005), more significant comorbidity burden (p = 0.039), more pain-predominant phenotypes (p = 0.004), lack of sexual activity (p < 0.001), and elevated scores in IC symptom indices (ICSI p = 0.003, ICPI p < 0.001), along with increased levels of the urine biomarker MIP-1β. However, pelvic floor muscle tenderness severity showed no significant correlation with bladder conditions such as bladder CT findings, urodynamic parameters, maximum bladder capacity, or glomerulation.

Pelvic floor muscle tenderness is not directly linked to bladder conditions in women with IC/BPS; however, it significantly influences the self-reported severity of IC symptoms. This underscores the importance of addressing pelvic floor muscle tenderness in the comprehensive management of IC/BPS, highlighting the necessity for synchronized multimodal treatments to alleviate overall symptom burden effectively and perceived severity in IC/BPS patients.