Crohn’s disease (CD) is a chronic immune-mediated inflammatory disorder characterized by transmural inflammation and a progressive course that frequently leads to structural complications such as intestinal fibrosis. Fibrostenosing disease represents a major clinical challenge, affecting up to 50% of patients over time and often requiring surgical intervention. Despite advances in anti-inflammatory therapies, no effective treatments currently exist to prevent or reverse established fibrosis. Intestinal fibrosis arises from a dysregulated tissue remodeling process driven by excessive extracellular matrix deposition and persistent activation of mesenchymal cells, particularly fibroblasts and myofibroblasts. This process is orchestrated through complex interactions between immune and non-immune cells and mediated by key signaling pathways, including transforming growth factor beta (TGF-β1) and the TL1A/DR3 axis. Genetic susceptibility, notably variants in NOD2 and other fibrosis-related genes, contributes not only to disease risk but also to phenotype progression. Epigenetic mechanisms, particularly microRNAs such as the miR-29 and miR-200 families, further modulate fibrogenesis and represent promising non-invasive biomarkers. Additionally, intestinal dysbiosis and specific microbial signatures, including reduced short-chain fatty acid-producing bacteria and the presence of adherent-invasive Escherichia coli, play a critical role in promoting fibrotic pathways. Mesenteric adipose tissue, especially creeping fat, also contributes to fibrosis through immune and metabolic signaling. Emerging biomarkers related to collagen metabolism and advances in molecular profiling are improving early detection strategies. Novel therapeutic approaches targeting fibrogenic pathways, including anti-TL1A agents, show promising preliminary results. A deeper understanding of these mechanisms is essential to develop effective antifibrotic therapies and improve long-term outcomes in CD.

Immunotherapy with immune checkpoint inhibitors (ICIs) has represented a major breakthrough in the treatment of multiple solid and hematological malignancies, significantly improving survival and tumor control. However, the blockade of immune regulatory pathways such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) is associated with the development of immune-related adverse events, among which immune-mediated colitis (IMC) constitutes one of the most relevant gastrointestinal complications due to its frequency, potential severity, and impact on the continuation of oncologic treatment. IMC typically presents with diarrhea, abdominal pain, and gastrointestinal bleeding, and may progress to severe, life-threatening forms. Its incidence varies according to the type of ICI, and is higher with CTLA-4 inhibitors and particularly elevated with combination therapies. The pathophysiology is complex and multifactorial, involving dysregulated activation of proinflammatory T lymphocytes, impairment of immune regulatory mechanisms, disruption of the intestinal epithelial barrier, and a key modulatory role of the gut microbiota. Diagnosis requires a high index of clinical suspicion and relies on endoscopy with biopsies, given the poor correlation between clinical severity and endoscopic or histological findings. Fecal biomarkers, such as calprotectin and lactoferrin, are useful for risk stratification and disease monitoring. Treatment is based on a stepwise immunosuppressive approach, with corticosteroids as first-line therapy and biologic agents such as infliximab or vedolizumab in refractory cases. Emerging strategies, including fecal microbiota transplantation, offer new therapeutic perspectives. This article provides a comprehensive review of the current evidence on the epidemiology, pathophysiology, diagnosis, and management of IMC, as well as future challenges and opportunities in its clinical management.