Integrating anorectal manometry, balloon expulsion, and defecography: insights into diagnosing pelvic floor...

Defecatory dysfunction (DD) is a common cause of chronic constipation resulting from functional abnormalities or structural pelvic pathologies. Accurate diagnosis requires combining anorectal manometry (ARM), balloon expulsion test (BET), and defecography. This study evaluates the diagnostic utility of these modalities and explores uncertainties in their performance and interpretation. This retrospective study included 325 adult patients assessed for DD between 2020 and 2023. All patients went through ARM, BET in the left lateral position, and defecography. Statistical associations between test outcomes were analyzed to assess diagnostic concordance and significance. A strong correlation was observed between ARM and defecography, with 65% of patients with normal anal relaxation on ARM achieving normal rectal evacuation on defecography (P < 0.0001). Conversely, patients with paradoxical contraction during ARM demonstrated a higher likelihood of evacuation failure. BET demonstrated high specificity but limited sensitivity in association with relaxation on ARM and evacuation on defecography. BET failure did not demonstrate a significant association with the presence of pelvic floor pathologies. Combining ARM, BET, and defecography provides a comprehensive framework for diagnosing DD, addressing its functional and structural components. This integrated approach facilitates targeted interventions, ultimately improving clinical outcomes.NEW & NOTEWORTHY This study demonstrates that anal relaxation on anorectal manometry significantly correlates with rectal evacuation on defecography, supporting its physiological relevance. Balloon expulsion in the left lateral position shows high specificity but low sensitivity for defecatory dysfunction. Notably, balloon expulsion test (BET) failure was not associated with anatomical abnormalities. An integrated diagnostic approach using anorectal manometry (ARM), BET, and defecography enhances accuracy in distinguishing functional from structural causes of pelvic floor dysfunction.