The purpose of this study is to demonstrate, in patients treated with adalimumab, the efficacy of proctological surgery in anoperineal fistula healing after the removal of seton drain.

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.