Comparison of Anorectal Manometry to Endoanal Ultrasound in the Evaluation of Fecal Incontinence

Background: Fecal incontinence (FI) is a common clinical condition with a negative impact on the quality of life. Commonly performed tests to evaluate FI include anorectal manometry (ARM) and endoanal ultrasonography (EAU). Objective of our study was to compare the results of these 2 tests in a cohort of patients with FI. Methods: Retrospective study of 27 patients (20 women) referred to the gastrointestinal motility clinic for FI. EAU and ARM were performed in all patients. Demographic data and information regarding etiology of FI was also recorded. Results: Mean age of the patients was 56 years (range 26-87 years). Etiology of FI was obstetric trauma in 4, pelvic surgery in 9, pelvic trauma in 3, pelvic radiation in I, and idiopathic in 8. Based on the ARM data, 14 of 27 had a weak external sphincter squeeze pressure and 3 had impaired rectal sensation, whereas with the EAU there was thinning of the external anal sphincter in 3 and complete disruption in 1, and abnormalities of the internal anal sphincter (IAS) in 7 of 27 with thinning, and defects. Overall, only 2 of 27 had normal findings by combined ARM and EAU. Conclusions: Although the yield of finding major sphincter defects was low, only a small percentage of patients had a normal ARM or EAU. When there are degrees of external anal sphincter thinning or partial or complete disruption of the sphincters, a good correlation with ARM is achieved. EAU and ARM are complimentary investigations for the thorough assessment of the anal sphincter apparatus.