Please select the eligibility criteria that correspond to the clinical trial below.
Title: Azathioprine in the Prevention of Ileal Crohn's Disease Postoperative Recurrence: Systematic Versus Endoscopic-directed Treatment. A Multi-center, Randomized, Clinical Practice Evaluation Study.
Brief Summary: The objective of this study is to evaluate if in the prevention of postoperative recurrence of ileal Crohn's disease immediate initiation of azathioprine postoperatively is superior to delayed (6- 12 mths.) introduction of azathioprine upon disease recurrence assessed by endoscopic criteria. The primary endpoint, disease recurrence, encompasses symptomatic and surgical recurrence as well as severe endoscopic lesions at the final, 2 year, assessment.


Options:
A: Inclusion Criteria:

* Age ≥ 18 years of age at the time of signing informed consent.
* Patients with Crohn's disease who have undergone an ileocecal/ileocolic resection (L1 or L3). The study and the treatment must be initiated within the two first weeks after the resection (+/- 5 days).
* Patients with surgical reconstruction by ileocolic anastomosis.
* Women of childbearing age must not be breastfeeding and must have a negative urine pregnancy test and must agree to use contraceptive methods with a \<1% failure rate (e.g., sexual abstinence, oral contraceptives, double barrier methods, intrauterine devices), unless they only have one partner who is sterile.
* Patients who have signed and dated the informed consent form before performing any specific screening study procedure.

Exclusion Criteria:

* Resection that requieres Temporal ileostomy.
* Urgency resection which doesn´t permit the initial assessment protocol completion.
* Resection due to inactive short indolent stenosis (\<10 cm).
* Resection with mucosal macroscopic residual disease in anastomosis.
* Previous intolerance or adverse reaction (moderate or severe) to adalimumab or azathioprine.
* Any contraindications or unwillingness to perform the scheduled colonoscopies or resonances.
* Contraindications to Adalimumab treatment, among which the following are included: active tuberculosis, severe infections such as sepsis or opportunistic infections, moderate or severe heart failure (NYHA class III or IV), central nervous system demyelinating diseases, history of malignant neoplasm or autoimmune diseases.
* Severe associated Extraintestinal manifestations.
* Previous postoperative recurrence prevention treatments with adalimumab, asathiprine o mercaptopurine which resulted in failure.
* Any other disease or patient condition that according to investigator criteria, inadequates patient´s participation in the study.
B: 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.
C: Inclusion Criteria:

* men/women \> 18 years of age
* curative resection/ileocolonic anastomosis for Crohn's disease
* may have received previously received infliximab
* if on oral aminosalicylates or corticosteroids, dose must be stable for 4 weeks prior to surgery
* if on 6-mercaptopurine,azathioprine or methotrexate,individual must have been on it for minimum of 3 months prior to surgery with stable dose for 4 weeks
* men and women must use adequate birth control for duration of study and for 6 months after receiving the last infusion
* antibiotics for treatment of Crohn's disease must be discontinued within 12 weeks after surgery; antibiotics are allowable throughout study as long as primary purpose of antibiotic therapy is not for primary treatment of Crohn's disease
* screening lab results must meet screening criteria (hemoglobin = or \> 8.5g/dL; Serum glutamic oxaloacetic transaminase ,3 times upper normal limit,platelets =or\> 100 x 10 9th/L; lymphocytes count =or\> 0.5 x 10 9th/L and neutrophils =or\> 1.0 x 10 9th/L
* have a documented negative reaction to a purified protein derivative skin test performed within 3 months prior to baseline
* have a normal chest radiograph results within 3 months prior to baseline
* are capable of providing written informed consent and obtained prior to conducting any protocol-specified procedures
* willing to adhere to the study visit schedule and other protocol requirements
* are considered eligible according to the tuberculosis eligibility assessment, screening and early detection of reactivation rules
* patients who undergo resective surgery and primary ileocolonic anastomosis with a temporary ileostomy upon takedown of the diverting ileostomy.

Exclusion Criteria:

* patients with greater than 10 years of Crohn's disease requiring first resection of a short (\<10cm) fibrostenotic stricture
* macroscopically active disease at anastomosis at time of surgery
* presence of stoma
* prior severe infusion reaction to infliximab
* history of anaphylaxis to murine products or other chimeric proteins
* any of the following medications taken within 12 weeks of surgery: cyclosporine, tacrolimus, sirolimus, mycophenolate mofetil, investigational drugs, or medications targeted at reducing tumor necrosis factor
* have a positive stool culture for enteric pathogens, pathogenic ova or parasites, or Clostridium difficile toxin and have clinically significant signs of an enteric infection at screening
* women who are pregnant, nursing or planning pregnancy during the trial or within 6 months after the last infusion
* patient with active tuberculosis, patient newly diagnosed with latent tuberculosis who's receiving tuberculosis prophylaxis, patient with recent close contact to individual with active tuberculosis
* have or have had opportunistic infection within 6 months of screening
* have chest radiograph within 3 months prior to screening that shows malignancy, infection, or abnormalities suggestive of tuberculosis
* documentation of seropositive for HIV
* documentation of a positive test for hepatitis B surface antigen or a history of documented hepatitis C
* have current signs/symptoms of systemic lupus erythematosus, or severe progressive, or uncontrolled renal, hepatic, hematologic, gastrointestinal, endocrine, pulmonary, cardiac, neurologic or cerebral diseases
* presence of a transplanted solid organ (with exception of corneal transplant \> 3 months prior to randomization)
* Have any current or known malignancy or have history of malignancy within 5 years of screening(except for squamous or basal cell carcinoma of the skin that has been fully excised with no evidence of recurrence)
* have history of lymphoproliferative disease or splenomegaly
* have known substance abuse(drug/alcohol)/dependency within the previous 3 years, history of noncompliance with medical regimens, or other condition that may interfere with adherence to protocol requirements
* are unwilling/unable to undergo multiple venipunctures because of poor tolerability or lack of easy access
* known history of demyelinating disease
* a chronic or recurrent infectious disease
* serious infection, hospitalization for infection, or treatment with IV antibiotics for infection within 2 months prior to randomization
* a serious concomitant illness that may interfere with participation in trial
* concomitant diagnosis/history of congestive heart failure
* current use of prescription doses or chronic/frequent use of non-steroidal anti-inflammatory drugs
* ulcerative colitis
* concurrent participation in another investigative trial
* use of any investigational drug within 30 days prior to randomization
D: 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.

Answer: D