This study will be a multicentre prospective randomized trial to assess the percentage of patients with IBD who, after stopping anti-TNF treatment, have sustained clinical remission at one year compared to those in which the treatment is continued at stable doses

A multicentre prospective randomized trial.

Hypothesis:

The discontinuation of anti-TNF treatment in inflammatory bowel disease (IBD) patients in clinical remission is associated with an increased risk of recurrence compared with maintaining such treatment.

Main objective:

To assess the percentage of patients with IBD who, after stopping anti-TNF treatment, have sustained clinical remission at one year compared to those in which the treatment is continued at stable doses

Secondary objectives:

To compare treatment discontinuation vs. treatment continuation of anti-TNF agents in patients with Crohn´s disease or ulcerative colitis in terms of:

1. remission (relapse-free) time,
2. phenotype changes with both strategies
3. mucosal healing,
4. radiologic healing
5. impact on quality of life and productivity
6. safety
7. to identify relapse predictive factors.
8. To identify relapse predictive factors after anti-TNF drug discontinuation
9. Determining the profile of serum cytokines in patients with both strategies, depending on drug exposure and if maintained clinical remission or relapse.

Planned number of subject to be included: 194

The participation of at 50 hospitals in Spain with an inclusion of about 5 patients per hospital is required..

Case report Form was designed on REDCap (a free, secure, web-based application designed to support data capture for research studies).

Inclusion Criteria:

• Patients diagnosed with IBD by the usual criteria; both Crohn's and ulcerative colitis disease.
• Patients older than 18 years.
• In the case of patients with Crohn's disease the indication treatment with anti-TNF it must have been for luminal involvement (no perianal).
• Are currently in clinical remission.
• The clinical remission period with the drug at non-intensified dose it must have been at least 6 months.

The administration of ≥10 mg/kg/8 weeks or 5 mg / kg / ≤ 4 weeks, in the case of infliximab, and 40 mg / week, in the case of adalimumab, is considered an intensified dose.

• At the time of inclusion, the patient should be receiving concomitant immunosuppressants (thiopurine or methotrexate) to anti-TNF treatment, and must have received these immunosuppressive drugs at stable doses for at least the last 3 months.
• In patients with Crohn's disease or ulcerative colitis disease, at baseline colonoscopy (made up to 3 months prior to the screening visit) should not be "significant" injuries.
• In the case of patients with Crohn's ileal or ileocolic disease, in magnetic resonance whole should not be "significant" injuries.(made up to 3 months prior to the screening visit)

Exclusion Criteria:

• Age less than 18 years.
• Patients who have been treated with anti-TNF for other indication than the IBD.
• Patients with Crohn's disease in which the indication for treatment with anti-TNF has been the perianal involvement (or luminal and perianal both); or showing active perianal disease at the time of inclusion.
• Patients who are not receiving concomitant treatment with immunosuppressants (thiopurine or methotrexate) at the moment (and in the previous 3 months).
• Patients undergoing bowel resection surgery; therefore, patients who began anti-TNF therapy to prevent or treat postoperative recurrence in Crohn's disease will be excluded.
• Presence of "significant" endoscopic or radiological lesions
• Advanced chronic illness or any other condition that prevents the patient from coming to the clinic for monitoring or follow-up.
• Patients who are pregnant, breastfeeding or intending to become pregnant during the course of the study.
• Refusal to give consent for participation in the study.