Comparison of digital and manometric assessment of anal sphincter function

Anal sphincter function was assessed by digital examination and anal canal manometry in 66 patients and controls. Digital scores were allotted by using visual analogue scales for basal and squeeze sphincter function and were compared with the corresponding pressures. There were good correlations between digital basal score and maximum basal pressure (Spearman rank correlation coefficient rs = 0·56, P <0·001), and digital squeeze score and maximum squeeze pressure (rs = 0·72, P <0·001). There were wide ranges of sphincter function on digital and manometric assessment with considerable overlap between patient groups. Digital scores detected differences in sphincter function between patient groups as accurately as manometry. The sensitivities and specificities of digital scores and anal canal manometry in segregating continent and incontinent patients were similar. It was concluded that digital estimation was equally as good an assessment of anal sphincter function as anal canal manometry.