Anal Crohn Fistula Surgery

Inclusion Criteria: * male or female 18 years or older, * women of childbearing age who use an effective contraception method or women incapable of becoming pregnant \[(i.e. postmenopausal women for 1 year or surgically sterile (hysterectomy and/or bilateral oophorectomy)\], * Patient with fistulizing anoperineal Crohn's disease. Anoperineal fistulas can be associated with ileal, colic or rectal lesions, * Patient with at least 1 anoperineal fistula drained with a seton for more than 1 month, * Patient treated with adalimumab for more than 1 month, * Patient who agrees to undergo surgery for its drained fistula(s), * Patient with immunosuppressive therapy (azathioprine, 6-mercaptopurine ou methotrexate) stable for at least 3 months or patients without immunosuppressive therapy, * Patient who gave signed written informed consent after having received verbal explanation and written information related to the trial. Exclusion Criteria: * Pregnant or breastfeeding women, * Patient having a perineal abscess, * Patient with a high anovaginal fistula that cannot be treated, according to the investigator ,with fistulotomy, gluing, biodegradable plug or advancement flap, * Patient treated with a daily dose of corticosteroids of more than 20 mg (a dose of more than 20 mg daily will be authorized during the study), * Contraindication to proctological surgery on the drained fistula(s), * Patient presenting with somatic or psychic signs or symptoms that are not compatible with his/her participation in the trial according to the investigator, * Patient who participate in another clinical trial.