The goal of this observational, multicenter, descriptive, prospective, and longitudinal study is to evaluate the impact of IBD activity on frailty in a prospective and longitudinal cohort of patients with IBD, and also to assess the impact of frailty on the risk of hospitalization and mortality in patients with IBD aged ≥60 years.

The main questions it aims to answer are:

1. Can frailty and consequently the risk of complications (adverse events, hospitalization, and mortality) be reversed through proactive treatment in frail patients with active inflammatory bowel disease?
2. Which frailty index is the most effective for predicting the risk of complications in patients with active inflammatory bowel disease? At inclusion, clinical frailty indices will be calculated. Additionally, clinical variables related to IBD and comorbidities will be recorded. During follow ups visits frailty, comorbidities, IBD activity, changes in medical treatment for IBD, adverse effects, hospitalizations, and mortality will be reassessed.

All consecutive patients meeting the selection criteria in the participating centres will be invited to participate.

-At inclusion, 4 clinical frailty indices (CFS-Clinical Frailty Scale, FRAGIL-VIG, Fried, VES-13) will be calculated. In addition, clinical variables on IBD (diagnosis, phenotype, extraintestinal manifestations, perianal disease, time of evolution of the disease, active treatments at the time of inclusion, treatment initiated, diagnostic tests available at the time of inclusion) and comorbidities (allowing calculation of the Charlson and Cumulative Illness Rating Scale for Geriatriscs [CIRS-G] indices) will be recorded.

Follow-up: a total of 3 follow-up visits will be conducted (at 3, 6 and 12 months) where frailty, comorbidities, IBD activity, changes in IBD medical treatment, adverse effects, hospitalisations and mortality will be reassessed.

Inclusion Criteria:

• Patients aged ≥60 years with IBD (Crohn's disease or ulcerative colitis) diagnosed according to ECCO criteria and under follow-up in the IBD units of participating centers.
• Initiation of medical treatment (oral mesalazine, topical or systemic corticosteroids, immunosuppressants, and/or biologics) due to clinical activity based on PRO2 scales (UC: PRO >4; CD: PRO2 >14) and/or biological activity (fecal calprotectin ≥500 mg/kg, C-reactive protein ≥10 mg/L).
• Signed informed consent for inclusion.

Exclusion Criteria:

• Lack or withdrawal of informed consent.
• Unclassified/indeterminate colitis.
• Change in medical treatment solely due to adverse events.
• Initiation of treatment only with salicylates and/or topical steroids for disease activity.
• Treatment intensification to manage disease activity.
• Patients with an ostomy.
• Comorbidities with a life expectancy of less than one year.

Patients aged ≥60 years with a diagnosis of IBD and clinical and/or biological disease activity.