Clinical application of anorectal manometry

Anal sphincter manometry provides an objective assessment of one aspect of the anorectal sphincter mechanism. It provides a far more reliable indicator of anal sphincter tone than can be achieved by digital examination. The relative contribution of the voluntary and involuntary components can be assessed, and the integrity of reflex inhibition to rectal distention can be evaluated. Anal sphincter manometry may provide direct evidence of the underlying problem as in Hirschsprung's disease or anal sphincter hypertonia. Radial cross-sectional analysis can provide identification of surgically repairable segmental defects as in the case of traumatic injury. On the other hand, the finding of a normal anal sphincter profile may serve to redirect one's investigational efforts to other components of the sphincter apparatus.