Immunological Characteristics of Preclinical IBD

Inclusion criteria Patients from cohort A will be included if they fulfill all the following Who May Qualify: - Male or female ≥18 years of age at baseline. - New diagnosis of IBD during a CRC screening colonoscopy, based on the criteria from the European Crohn's and Colitis Organization (33, 34). - Presence of a chronic inflammatory infiltrate and histological diagnosis compatible with IBD. - The patient must be asymptomatic at diagnosis and without previous symptoms suggestive of IBD. - Time interval between the index colonoscopy and the baseline visit up to 3 months. Patients from cohort B will be included if they fulfill all the following Who May Qualify: - Male or female ≥18 years of age at baseline. - Recent diagnosis of IBD, with \<3 months from symptoms onset. - Time interval between the index colonoscopy and the baseline visit up to 3 months. Patients from cohort C will be included if they fulfill all the following Who May Qualify: - Male or female ≥18 years of age at baseline. - No endoscopic signs of IBD after a complete ileo-colonoscopy within the CRC screening program. - Time interval between the index colonoscopy and the baseline visit up to 3 months. Exclusion criteria Patients from cohort A will be excluded if they fulfill any the following Who Should NOT Join This Trial: - Identification of any enteropathogen in the stool culture. - Isolated findings of acute inflammatory infiltrate without signs of chronicity. - Previous or current diagnosis of microscopic colitis. - Alteration in biomarkers in blood or stool will not constitute an exclusion criterion. Patients from cohort B will be excluded if they fulfill any the following Who Should NOT Join This Trial: \- Previous use of immunomodulators or biologics for any condition. Patients from cohort C will be excluded if they fulfill any the following Who Should NOT Join This Trial: - Any gastrointestinal symptoms at baseline. - Previous use of immunomodulators or biologics for any condition. Always talk to your doctor about whether this trial is right for you.