Granulomatous appendicitis can be idiopathic or due to a number of specific causes. Idiopathic granulomatous appendicitis is regarded as a separate disease entity and usually has a benign course. We report on a case of granulomatous appendicitis, which progressed to fulminant Crohn's colitis shortly after appendicectomy. During the treatment with intravenous steroid, torrential gastro-intestinal bleeding developed and emergency subtotal colectomy had to be performed. The clinical and histological features of the case are presented and the literature on granulomatous appendicitis reviewed.