[Impact of endoscopy in Crohn's disease]

Two types of endoscopic lesions are observed in Crohn's disease (CD): active lesions or scars, frequently associated. Following their localization at different sites of the digestive tract, they are defining the type of disease. Ileo-colonoscopy is an important step of the initial characterization of the lesions, completed with biopsies helful for the differential diagnosis between CD and ulcerative colitis or infectious colitis An endoscopy is only repeated in front of a new clinical problem or when a change of treatment is required. In case of severe colitis, colonoscopy may detect septic lesions as well as deep ulcers indicating severe evolution with a bad prognosis. After surgery, in most of the cases ileocolonoscopy detects recurrent lesions whose severity is linked to an unfavourable clinical evolution and permits therapeutic adaptation. Since the risk of colorectal cancer in CD predominant in the colon is probaly underestimated, a systematic colonoscopy after 8 to 10 years of evolution should be performed for the screening of malignant lesions. Colonoscopy is also useful for the treatment of complications of CD, i. e. dilatation of benign strictures, as well as localization and treatment of distal bleeding. Upper digestive tract endoscopy, endosonography, enteroscopy, videocapsule and endoscopic retrograde cholangio-pancreatography are other contributive methods within the field of correct indications.