Perianal Crohn's disease

Perianal disease in Crohn's disease is a difficult matter to deal with. The indication for therapy is not always clear in this disease with a relatively mild natural course. More confusion is caused by the fact that not all disease in the perianal region in a patient with Crohn's has to be Crohn-related. The usual ailments such as haemorrhoids may occur in a patient with Crohn's disease. The treatment has to be as for every patient. Primary mucosal and submucosal Crohn's disease in the anal canal has to be treated like uncomplicated Crohn's disease in the rest of the gastrointestinal tract with appropriate medication.

The option for therapy in complicated abdominal Crohn's disease, most often resection, is not available in perianal disease without giving up faecal continence. One has to make a compromise, wishing to treat the disease as radically as possible, while preserving faecal continence as much as possible.

The basis for treatment for complicated Crohn's disease is medical treatment for the primary disease. The choice in surgical options depends on the type of complication. A different strategy is needed for each type of complication. The therapy is different for perianal abscesses, rectovaginal fistulas, stenosis, high perianal fistulas and low perianal fistulas. It is proposed to treat abscesses by early incision and drainage, rectovaginal fistulas by a mucosal advancement anoplasty, high perianal fistulas by a seton procedure, low perianal fistulas by fistulotomy, and stenosis by mild dilatation. Rectal excision is reserved for perianal disease combined with colorectal involvement refractory to therapy.

The high incidence of poor healing following radical proctectomy led to a staged procedure in which the rectum is resected to the pelvic floor, followed, if necessary, at a later stage by perineal resection of the retained anal canal.