Please select the eligibility criteria that correspond to the clinical trial below.
Title: Double-blind, Double-dummy, Randomised, Multicentre, Comparative Study on the Efficacy and Safety of Azathioprine Versus Mesalazine for Prevention of Clinical Relapses in Crohn's Disease Patients With Postoperative Moderate or Severe Endoscopic Recurrence
Brief Summary: This study aims to compare azathioprine versus mesalazine tablets for the prevention of clinical relapse in postoperative Crohn's disease (CD) patients with moderate or severe endoscopic recurrence.


Options:
A: Inclusion Criteria:

* Signed informed consent,
* Man or woman between 18 and 70 years of age,
* Diagnosis of Crohn's disease confirmed by endoscopic and histological, or endoscopic and radiological criteria within one year or by histopathological criteria during resection,
* Clinical remission defined as Crohn´s Disease Activity Index (CDAI) \< 200, within the last two weeks. No clinical relapse due to Crohn's disease since resection,
* Moderate (i2a) or severe endoscopic recurrence (i3-i4) within 6 to 24 months after curative resection of the terminal ileum and partial colectomy with ileocolonic resection for complications of ileal Crohn´s disease and with a construction of an ileocolonic anastomosis,
* Within the neoterminal ileum at least more than 5 aphthous lesions with normal mucosa between the lesions, or skip areas of larger lesions,
* Negative pregnancy test at screening visit in females of childbearing potential,
* Use of appropriate contraceptive methods for females of childbearing potential and males with procreative capacity during treatment and at least up to 3 months after the end of treatment.

Exclusion Criteria:

* Lesions confined to the ileocolonic anastomosis (i.e., \< 1 cm in length)
* Short bowel syndrome,
* Serious secondary illnesses of an acute or chronic nature, which in the opinion of the Investigator renders the patient unsuitable for inclusion into the study,
* Serum creatinine levels exceeding 1.5 mg/dL or 130 umol/L,
* Presence of an ileo-/colonic stoma,
* Genotype: thiopurine methyltransferase (TPMT) -/-,
* Known previous or concurrent malignancy (other than that considered surgically cured, with no evidence for recurrence for 5 years),
* Treatment with cytostatics or immunosuppressants, methotrexate, cyclosporine, 6-MP, Azathioprine, 6-TG or anti-TFN-alpha therapy since resection; postoperative treatment with corticosteroids for more than 4 weeks or postoperative treatment with oral antibiotics (e.g., metronidazole, ciprofloxacin) for more than 4 weeks,
* Application of non-steroidal anti-inflammatory drugs (NSAIDS) within 2 weeks before Screening visit except low dose acetylsalicylic acid and except paracetamol,
* Known intolerance/hypersensitivity to study drugs or drugs of similar chemical structure or pharmacological profile,
* Scheduled or intended active immunisation with living vaccines within the next 12 months,
* Well-founded doubt about the patient's cooperation,
* Existing pregnancy, lactation, or intended pregnancy or impregnation within the next 15 months,
* Non-use of appropriate contraceptives in males with procreative capacity and females of childbearing potential (e.g. condoms for males, intrauterine device \[IUD\], hormonal contraception for females, or a means of contraception for a particular patient considered adequate by the responsible investigator) during treatment and within 3 months after the end of treatment,
* Participation in another clinical trial within the last 30 days, simultaneous participation in another clinical trial, or previous participation in this trial,
* Present stricture plasty (no exclusion if the present stricture plasty was macroscopically without any relevant finding of inflammation seen during index surgery.
B: Inclusion Criteria:

* age 16 - 75 years
* diagnosis of Crohn's disease within the past 4 years
* no previous treatment with corticosteroids, antimetabolites, or biologic agents.
* Active Crohn's disease, defined by a Crohn's Disease Activity Index (CDAI)20 score of greater than 200 points for a minimum of 2 weeks prior to randomization.

Exclusion Criteria:

* immediate need for surgery
* symptomatic stenosis or ileal/colonic strictures with prestenotic dilatation;
* signs, symptoms or laboratory tests indicating severe, medical disease;
* documented chronic infection
* a positive stool culture for pathogens
* a positive tuberculin test or a chest radiograph consistent with tuberculosis.
* malignancy
* allergy to murine proteins
* pregnancy
* substance abuse
C: Inclusion Criteria:

* \> 18 yr old
* diagnosis of Crohn's disease
* intestinal lesions demonstrated during the last 6 months
* disease duration \< 6 months
* patients at high risk of disabling disease (having 2 criteria out of the 3 following: age \< 40, perinanal disease, steroid for the first flare)

Exclusion Criteria:

* prior prescription of immunosuppressants
* severe course requiring early immunosuppressants (steroid resistance, xtensive disease, disabling perianal disease)
* intestinal resection
* active infectious disease including HIV
* hepatic failure
* renal failure
* pregnancy
* high probability of poor compliance
D: Inclusion Criteria:

* Diagnosis of Crohns Disease for at least 6 weeks
* Moderate to severe disease activity (CDAI \>= 220 and \<=450)
* No history of azathioprine, 6-MP (6 Mercaptopurine), or biologic treatments
* Are either: Corticosteriod-dependent, OR considered for a 2nd (or greater) course of corticosteriod, OR 5-ASA failures, Or Budesonide failures

Exclusion Criteria:

* History of abdominal surgery within the last 6 months
* Have an ostomy or stoma \[An operation to create an opening from an area inside the body to the outside\]
* Are pregnant, nursing, or planning pregnancy (both men and women)
* Serious simultaneous illness that could interfere with study participation
* Use of any investigational drug within 30 days
* Have a concomitant diagnosis or any history of congestive heart failure
* Weigh more than 140 kilograms (or 310 pounds)

Answer: A