Anorectal nomenclature: fundamental terminology.

There is lack of agreement on the definitions of the anal canal and its parts. To facilitate mutual understanding and communication between workers, it is highly desirable that a set of agreed-upon definitions be developed. The development of the different definitions and their purposes is followed and they are analyzed. As a basis for discussion, a possible revised entry for the next edition of Terminologia Anatomica is presented. Draft definitions of the terms in the entry are provided. Practitioners are invited to become involved in the process of developing agreement on definitions by providing comments and criticism.