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:

1. Scheduled surgery for Crohn's disease (CD) with ileocolonic resection. Diagnosis of CD confirmed at least 4 months prior to surgery based on radiology and/or endoscopy.
2. Having an increased risk for postoperative relapse for any of the following reasons: (1) active inflammatory disease with C-reactive protein level (CRP) elevated above 10 mg/L, or the use of antibiotics, steroids or biological therapy including infliximab for active ileal disease within 2 months before surgery which were administered for Crohn's disease and not for another unrelated intercurrent inflammatory or infectious disease; (2) perforating disease defined as the presence of entero-enteric or enterocutaneous fistulas or perivisceral abscess formation within 2 months before surgery. Perianal fistulizing disease will not be considered as an indication of perforating disease in the ileum or right-sided colon. (3) Previous ileo-colonic resection, (4) active smoking, (5) age below 30.
3. Males and females 16-75 years old.
4. Curative surgical resection. All macroscopically inflamed colonic segments (except for anorectal involvement) are to be removed at surgery. Stricturoplasties in small bowel segments not involving the anastomotic region are allowed.
5. Patients able to start oral nutrition and oral therapy within 14 days from surgery.
6. Patients able and willing to give written informed consent
7. Women of childbearing potential should have a negative pregnancy test at inclusion.

Exclusion Criteria:

1. Patients who only had strictureplasties or ileal/colonic resection without a new ileo-colonic anastomosis. Patients with ileorectal anastomosis.
2. Patients with no increased risk of postoperative relapse as defined before.
3. Patients with a known intolerance to azathioprine/6-mercaptopurine or with known homozygous thiopurine methyltransferase-low mutation.
4. Patients in whom more than 100 cm of small bowel has been previously resected.
5. Patients with active perianal disease or colorectal stenosis precluding ileocolonoscopy
6. Patients with sepsis or other postoperative complications necessitating use of antibiotics for more than 14 days after surgery.
7. Patients with liver test abnormalities (serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, bilirubin \> 2 ULN), leucopenia (\<3000 white blood cell count /µL, \<1500 neutrophils /µL), thrombopenia with \< 50.000 platelets/mm3.
8. Patients with severe renal, pulmonary or cardiac disease.
9. Pregnant or lactating women.
10. Ongoing alcohol or substance abuse.
11. Ongoing or recent (within 6 months) infectious disease (viral hepatitis, tuberculosis, AIDS, Herpes zoster related disease).
12. Known malignancy 5 years from surgery except for superficial epithelioma of the skin with curative resection.
B: Inclusion Criteria:

* clinical diagnosis of Crohn's and proven history of disease
* patient undergone surgical resection with creation of a primary anastomosis

Exclusion Criteria:

* endoscopically inaccessible anastomosis by standard colonoscopy
* presence of an end stoma
* pregnancy
* suspected perforation of the gastrointestinal tract
* presence of certain unsuitable comorbidities
C: 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.
D: Inclusion Criteria:

1. Subjects 16 years of age or older
2. Diagnosis of Crohn's disease
3. Resection of ileocolonic Crohn's disease and small bowel to colonic anastomosis within 30 days of randomization
4. Able to provide informed written consent
5. Women of child-bearing potential with a negative serum pregnancy test, and/or use of effective contraception

Exclusion Criteria:

1. Use of perioperative steroids in tapering doses and anti-diarrheal agents
2. Treatment with a TNF-antagonist in the 8 weeks prior to resection
3. Clinically significant Crohn's disease elsewhere in the GI tract
4. Clinically documented short bowel syndrome
5. Serious disease other than Crohn's disease
6. Impaired liver or renal function
7. History of cancer with less than 2 years disease-free state
8. Abnormal Laboratory values
9. Alcohol or drug abuse
10. Some psychiatric conditions
11. Patients using other study medications
12. Patients who are unable to attend study visits or comply with study procedures
13. Positive pregnancy test

Answer: C