ANAL PATHOLOGY IN PATIENTS WITH CROHNS-DISEASE

Background: A distinctive feature of patients suffering from Crohn's d isease is a predisposition to develop a variety of anal complications. The aetiology of such conditions is unclear, and the reported inciden ce of anal involvement in Crohn's disease varies party due to the vari ous criteria used for classification. This study aims to review the ma nagement of patients with symptomatic anal pathology associated with C rohn's disease at St Vincent's Hospital, Melbourne. Methods: A databas e of 306 patients with Crohn's disease referred to the department betw een January 1978 and October 1994 was reviewed to identify those patie nts with symptomatic anal disease. The anal pathology was recorded and classified. Demographic data and the clinical and surgical history of the patient were recorded. Results: Of the 306 patients with Crohn's disease, 129 (42.4%) were identified as having symptomatic anal pathol ogy. Patients were likely to present with anal symptoms after they had been diagnosed as having intestinal Crohn's disease (46.1%). The comm onest presentations were perianal abscess (29.5%), anal fissure (27.6% ), and low anal fistula (26.7%). A minority of patients presented with high/complex anal fistulae (3.8%), or recto-vaginal fistulae (5.2%). Five per cent of patients had Crohn's disease localized to the anal ar ea. The pattern of intestinal disease in the remaining patients was sm all bowel 21.1%, small bowel and colon 31.9%, and colon 43.0%. A total of 244 local anal surgical procedures were performed on these patient s; the commonest of these were drainage of an abscess (38.5%), examina tion under anaesthetic (29.1%), and laying open of a low anal fistula (22.5%). Following surgical treatment, the recurrence rate for periana l abscesses was 13%, and for low anal fistulae 6%. Conclusions: The ma jority of patients with Crohn's disease who develop anal pathology hav e an excellent prognosis. A minority of patients develop complex anal fistulae and these remain a therapeutic challenge.