Clinical Outcome of EMG-Based Pelvic Floor Biofeedback in Patients With Constipation—Impact of Prior Anorectal Manometry/Balloon Expulsion Test for Patient Selection. A Retrospective Study

Introduction: Pelvic floor biofeedback therapy (BFT) is the mainstay treatment for dyssynergic defecation, a condition defined by the Rome criteria. This retrospective study compares outcomes between patients referred for EMG-based BFT after anorectal manometry and balloon expulsion testing (ARM group) and those referred directly without prior ARM (DR group). Methods: Records of 466 patients who underwent BFT by a single therapist between 2019 to 2023 were reviewed. Inclusion criteria of referral for constipation, no opioid use, and ≥ 2 BFT sessions yielded 208 patients: 137 in the ARM group and 71 in the DR group. Outcomes were assessed using the Colorectal-Anal Distress Inventory-8 (CRADI-8), abdominal pain and quality-of-life impact scores, and therapist/patient ratings. Statistical analysis included Fisher's exact and Wilcoxon rank-sum tests. Key Results: Of the 208 patients meeting criteria, 50% achieved successful outcomes and 50% were unsuccessful, including those lost to follow-up. Success rates did not differ significantly between the ARM and DR groups (p = 0.393), although the ARM group had worse baseline symptoms (CRADI-8, strain, and empty scores). A successful outcome was associated with significant improvements in the strain and emptying subscores of the CRADI-8, and in quality-of-life limitation scores in both groups. Higher body weight and the absence of documentation of anxiety/depression were associated with success. ARM diagnoses and balloon expulsion test results were not associated with outcomes. Conclusions & Inferences: Similar outcomes to BFT were seen in both ARM and DR groups. BFT should be initiated based on clinical assessment when ARM access is limited.