[Risk factors in the etiology of Crohn disease].

So far the aetiology of Crohn's disease remains unclear. Besides a genetic predisposition a causal role of environmental factors has been taken into consideration within the last time period. A number of case-control studies have consistently reported about an increased consumption of dietary sugar in patients with Crohn's disease as compared with controls. Furthermore cigarette smoking and the use of oral contraceptive drugs have been shown to increase disease risk. While the role of the former can be regarded as established the role of the latter still remains controversial.