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

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 (rs -.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.