Crohn's disease (CD) can lead to surgical resection in many cases, however, there is disagreement regarding the appropriate indication, timing and type of surgery that should be carried out. A study performed in Stockholm during 1955-1990 diagnosed and monitored 1936 patients with CD to investigate the factors determining the outcome after different types of surgery. A total of 73% of these patients had at least one bowel resection. Young age at onset, female gender and a history of perianal fistulae were associated with a higher, overall, 10-year cumulative recurrence rate. In addition, small bowel or ileocolonic involvement at onset also carried a higher risk of recurrent disease, particularly in women. Obstruction or failure of medical therapy as indications for surgery are also associated with more frequent recurrences.