Inclusion Criteria:  Male or female patients with age > 18 years Crohn's disease for at least 6 weeks, Clinically active with CDAI > 150 Active inflammation by endoscopy (CDEIS > 4) at baseline Not responder to conventional therapy or are intolerant to or have medical contraindications for such therapies and initiating treatment with adalimumab Patient followed in a center belonging to the GETAID network Fertile men and women of childbearing potential included in the protocol should use adequate methods of contraception according to study drug SMPCs. Written consent  Exclusion Criteria:  Short bowel syndrome, ostomy, symptomatic stricture, abscess, recent history of abdominal surgery (<3 months) Non-passable colonic stricture Previous intolerance to thiopurines or MTX Previous exposition to adalimumab Contra-indication to immunosuppressants or anti-TNF Others serious simultaneous illness that could interfere with study participation Planning pregnancy, pregnancy or lactation or absence of contraception Known substance abusers Use of any investigational drug within 30 days Adults protected by law