To estimate the prevalence of major perineal trauma in a urogynecological population, to test the predictive value of sonographic tear grading (Gillor algorithm) for anal incontinence (AI), AI bother score and St Mark's score, and to compare the predictive power of the Gillor algorithm with that of the residual-defect method.This was a retrospective study of 721 women attending a tertiary urogynecology unit between February 2019 and May 2021. All women underwent a standardized interview, including determination of St Mark's score and visual analog scale (VAS) bother score for AI, as well as exoanal (translabial) ultrasound with later offline analysis. Results were reported as the presence of a residual defect of the external anal sphincter (EAS), i.e. a discontinuity of ≥ 30° in ≥ 4/6 tomographic slices, and according to the Gillor algorithm (normal, Grade 3a, Grade 3b or Grade 3c/4).Mean age at assessment was 57 (range, 19-93) years and mean body mass index was 30 (range, 17-57) kg/mNeither the Gillor algorithm nor the residual-defect method of quantifying sphincter trauma on imaging is clearly superior in terms of predicting AI. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.