Introduction: Pelvic floor dyssynergia (PFD), a functional constipation subtype, is defined by paradoxical movement or relaxation failure of the pelvic floor muscles. In some countries, squatting posture is the predominant method for bowel evacuation. This position allows an increase in both hip flexion and obtuse anorectal angle facilitating stool evacuation. The aims were to determine if use of a foot stool will aid in balloon expulsion in patients with abnormal balloon expulsion test (BET) and if there is an anorectal manometry (ARM) metric which predicts successful evacuation with position change. We hypothesize that use of a stool will open the anorectal angle, facilitate balloon expulsion and can be used for treatment of dyssynergia.
Methods: Patients between ages 18-85 with functional constipation (ROME III criteria) referred for ARM were recruited. Once inclusion/exclusion criteria were met and informed consent obtained, a standard protocol for 3D-high resolution ARM was performed. BET was done with insertion of a 50 cc water filled lubricated balloon expulsion catheter. Patients were asked to defecate the balloon into the toilet. For patients unable to expel the balloon within normal limits (60 seconds), a plastic stool was placed around the toilet and the BET repeated.
Results: Over 7 months, 36 patients were recruited. 15 patients (42%) had an initial abnormal BET. 6 patients (40%) were able to expel the balloon using the stool. The remaining 9 patients (60%) still had an abnormal BET. Maximum sphincter and rectal (resting/squeeze) pressures, duration of sustained squeeze and intrarectal pressure did not correlate with ability to expel the balloon with use of the stool. However, patients with an abnormal BET who were able to expel the balloon with use of the stool had lower residual anal pressures compared to those who were unsuccessful (48 vs 77 mmHg, P=0.04) with an average percent relaxation of 32%.
Conclusion: We sought to assess a simple strategy to treat PFD and to find a predictor for success based on ARM metrics. 40% of patients who failed initial BET were able to expel the balloon with use of a stool. Though largely a negative study, significantly lower residual anal pressures (>20% relaxation) were seen in patients with an initial abnormal BET who were able to expel the balloon with the stool. This may be clinically relevant in patients who cannot expel the balloon but do not have a manometric diagnosis of dyssynergia. A major study limitation was the small sample size.