Surgical pathology and management of anorectal Crohn's disease.

The anorectal manifestations of Crohn's disease comprise a complex and heterogeneous group of conditions which fall into two main categories: primary lesions of the active disease process and secondary lesions resulting from healing of, or infective complications of, the primary lesions. The lesions are classified into distinct clinicopathological entities which may be used in assessing prognosis and determining appropriate treatment. A basic principle of management is that surgery should be avoided as far as possible in the presence of disease activity, but will frequently be necessary, and satisfactory, for secondary complications.