Fibrosis is characterized by a proliferation of fibroblasts and excessive extracellular matrix following chronic inflammation, and this replacement of organ tissue with fibrotic tissue causes a loss of function. Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract, and intestinal fibrosis is common in IBD patients, resulting in several complications that require surgery, such as a stricture or penetration. This review describes the pathogenesis and various factors involved in intestinal fibrosis in IBD, including cytokines, growth factors, epithelial-mesenchymal and endothelial-mesenchymal transitions, and gut microbiota. Furthermore, histopathologic findings and scoring systems used for stenosis in IBD are discussed, and differences in the fibrosis patterns of ulcerative colitis and Crohn’s disease are compared. Biomarkers and therapeutic agents targeting intestinal fibrosis are briefly mentioned at the end.

Sang-Jae Kwon, Jiyoung Yoon, Eun Hye Oh, Jeongseok Kim, Nam Seok Ham, Sung Wook Hwang, Sang Hyoung Park, Byong Duk Ye, Jeong-Sik Byeon, Seung-Jae Myung, Suk-Kyun Yang, and Dong-Hoon Yang. Gut and Liver 2021;15:579-87. https://doi.org/10.5009/gnl20145

The incidence of pediatric-onset inflammatory bowel disease (IBD) is on the rise, accounting for up to 25% of IBD cases. Pediatric IBD often has extensive bowel involvement with aggressive and rapidly progressing behavior compared to adult IBD. Because IBD has a high morbidity rate and can have a lifelong impact, successful transition from pediatric to adult care is important to maintain the continuity of care. Furthermore, successful transition facilitates appropriate development and psychosocial well-being among patients, as well as comprehensive and harmonious healthcare delivery amongst stakeholders. However, there are various obstacles related to patients, family, providers, and organizations that interfere with successful transition. Successful transition requires a flexible and tailored plan that is made according to the patient's developmental abilities and situation. This plan should be established through periodic interviews with the patient and family and through close collaboration with other care providers. Through a stepwise approach to the transition process, patients' knowledge and self-management skills can be improved. After preparation for the transition is completed and the obstacles are overcome, patients can be gradually moved to adult care. Finally, successful transition can increase patients' adherence to therapy, maintain the appropriate health status, improve patients' self-management, and promote self-reliance among patients.