Easy peroperative classification of perianal muscle as external or internal sphincter by means of diathermy.

Cutting tissues with coagulation current diathermy has some advantages in anorectal surgery. By evoking twitches in striated muscle and no similar reaction in smooth muscle, the technique facilitates the distinction between internal and external anal sphincter. Furthermore, cutting in this manner avoids the use of sharp instruments, thereby lowering the risk of accidental perioperative spread of blood-borne viral disease.