Abstract: Very early onset inflammatory bowel disease (veo-IBD) is an IBD that is developed and diagnosed before the age of 6 years. IBD is an inflammatory reaction of uncontrollable intestinal epithelial cells caused by autoimmune disorder which is resulted from pathogenic factors such as intestinal commensal bacteria and pathogens stimulated by environmental factors. In recent years, the incidence and the prevalence of veo-IBD have continued to rise, and the diagnosis of ulcerative colitis is more common and it is more serious condition and has longer course of the disease compared to older-onset IBD. For veo-IBD, in addition to early onset, recurrent abdominal pain, diarrhea, mucous bloody stool, growth retardation and severe perianal diseases, different pathogenic genes can cause different clinical manifestations. The article reviews the trend of veo-IBD in recent years, the main pathogenesis, clinical manifestations, diagnosis and treatment in veo-IBD.