The Outcomes of Endoanal Ultrasound and Three-Dimensional, High-Resolution Anorectal Manometry do not Predict Fecal Incontinence

Abstract

Endoanal ultrasound (EUS) is the gold standard for diagnosing anal sphincter defects often seen in patients with fecal incontinence (FI). Threedimensional, high-resolution anorectal manometry (3D-HRARM) is a newer technique that might also be used to diagnose sphincter defects. We aimed to investigate whether FI is associated with anal sphincter defects detected by EUS and 3D-HRARM. Retrospectively, we included all adult patients who had undergone EUS and 3D-HRARM for FI, between January 2012 and February 2015 (N = 37). During 3D-HRARM, the presence of sphincter defects was examined in rest and during maximal anal sphincter contraction. All patients also underwent a balloon retention test to objectively determine whether they suffered from FI for solid stool. Of the 37 patients, 12 patients (32%) suffered from FI. The presence of a sphincter defect detected with EUS, and with 3D-HRARM during contraction, was not associated with the prevalence of FI and no significant correlations were found between these variables. The presence of a sphincter defect, detected by 3D-HRARM in rest, was negatively correlated with the presence of FI (r s -.372, P = .024). Moreover, the prevalence of sphincter defects was lower in patients with FI, detected by 3D-HRARM in rest, than in patients without FI (13% versus 88%, P = .035). FI is not associated with anal sphincter defects detected by EUS and 3D-HRARM. The outcomes of EUS and 3D-HRARM do not thus predict the presence of FI. Instead, extensive anorectal function tests should be performed to form a complete picture of a patient's anorectal functions and to determine the underlying causes of FI.