Inflammatory bowel disease (IBD) is a chronic immune-related disease, which mainly affects the digestive tract. There are mainly two forms of the disease, including Crohn's disease (CD) and ulcerative colitis (UC).||Biologics have revolutionized the treatment of inflammatory bowel disease with good efficacy and safety. However, 20-50% of patients may not response to or lose response to biologics. Unfortunately, there has been no factors or measures that may predict the efficacy or safety of biologics.||In this study, a large prospective cohort study is conducted to evaluate the efficacy and safety of biologics (infliximab, adalimumab, vedolizumab, ustekinumab, and other approved biologics) in patients with inflammatory bowel disease in the real clinical practice. Meanwhile, a multi-omics approach involving transcriptomics, microbiome, proteomics, and metabolome, are adopted to explore biomarkers or factors that predict the therapeutic efficacy or safety of biologics. The mechanism underlie the disease will also be explored.