Pelvic floor investigations for bowel dysfunction (part 1): endoanal ultrasound

Abstract

Endoanal ultrasound is the gold-standard diagnostic tool for assessing the anal sphincter musculature. It is most frequently used to establish the cause of faecal incontinence symptoms, which often result from obstetric anal sphincter injuries. Visualised patterns of echogenicity reveal the texture of different kinds of muscle, potentially showing atrophy, defects and/or fragmentation. These can be examined in light of the patient's clinical history for signs of infection, scarring or anal cancers, as well as haemorrhoids, abscesses or fistulae. Different depth-of-field settings make it possible to view the subepithelium, longitudinal muscle and internal and external anal sphincters at different depths. Technological developments include three-dimensional imaging. Endoanal ultrasound is a valuable investigative modality for colorectal nurse specialists to be able to use and interpret to benefit the patient and improve their symptoms.