Endoanal ultrasound is now regarded as the gold standard for evaluating
anal sphincter pathology in the investigation of anal incontinence. The advent of
three-dimensional ultrasound has further improved our understanding of the twodimensional
technique. Endoanal ultrasound requires specialised equipment and its
relative invasiveness has prompted clinicians to explore alternative imaging techniques.
Transvaginal and transperineal ultrasound have been recently evaluated as alternative
imaging modalities. However, the need for technique standardisation, validation and
reporting is of paramount importance. We conducted a MEDLINE search (1950 to
February 2010) and critically reviewed studies using the three imaging techniques in
evaluating anal sphincter integrity.