%0 English Abstract %T [Pediatric very early onset inflammatory bowel disease: Role of pathology]. %A Drabent P %A Berrebi D %J Ann Pathol %V 43 %N 3 %D Jun 2023 28 %M 36863899 %F 0.411 %R 10.1016/j.annpat.2023.02.003 %X Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are a heterogeneous group of multifactorial pathologies, often polygenic, due to a dysregulated immune response in a genetically susceptible host. In children under 6 years of age, a significant proportion of IBD, named "very early onset inflammatory bowel diseases" (VEO-IBD), are monogenic disorders in more than one third of cases. Over 80 genes have been linked to VEO-IBD and pathological descriptions are sparce. In this clarification, we describe the clinical aspects of monogenic VEO-IBD and the main causative genes, as well as the various histological patterns observed in intestinal biopsies. The management of a patient with VEO-IBD should be a coordinated effort by a multidisciplinary team including pediatric gastroenterologists, immunologists, geneticists, and of course pediatric pathologists.