Inflammatory bowel disease（IBD）is a group of nonspecific chronic gastrointestinal inflammatory diseases with unknown etiology，including Crohn’s disease（CD），ulcerative colitis（UC）and undifferentiated IBD（IBD-U），among which IBD with onset less than 6 years old is called very-early-onset inflammatory bowel disease（VEO-IBD）. It is a special subgroup in children with IBD. Different from IBD in adults or older children， VEO-IBD has the characteristics of early onset， severe symptoms， and accompanied by perianal lesions. The children can have extensive gastrointestinal symptoms and severe growth retardation， and the effect of traditional drug treatment is poor. With the development and wide application of high-throughput gene sequencing technology， more than 70 related pathogenic genes have been discovered. This article systematically expounds the pathogenesis of VEO-IBD， focusing on the pathogenic mechanism of gene mutations， the microbiota-host relationship， and the guiding significance for precision medicine practice.

very-early-onset inflammatory bowel disease, pathogenesis, gene, immunity

炎症性肠病（IBD）是病因不明的一组非特异性慢性胃肠道炎症性疾病，包括克罗恩病（CD）、溃疡性结肠炎（UC）和未定型 IBD（IBDU），其中 <6岁起病的 IBD 称为极早发型炎症性肠病（VEO-IBD），是儿童 IBD 中的特殊亚组。不同于成人或较大儿童 IBD，VEO-IBD 具有发病早、症状重、肛周病变等特点，患儿可出现广泛胃肠道症状及严重的生长发育迟滞等表现，且对传统药物治疗反应不佳。VEO-IBD发病机制包括遗传、免疫、代谢、微生态、环境等多方面因素，其中遗传因素为主导因素，随着高通量基因测序技术的发展及广泛应用，现已发现70余种相关致病基因。文章围绕 VEO-IBD 发病机制进行系统阐述，重点讨论基因突变致病机制、微生物—宿主关系以及对精准医疗实践的指导意义。

极早发型炎症性肠病, 发病机制, 基因, 免疫