We found subtypes of IBD have significant causal effects on serum biomarkers using IVW, including ANCA (p = 3.02e-5), CBir (p = 5.98e-16), ASCA-IgA (p = 2.74e-10), and ASCA-IgG (p = 1.97e-9) (Bonferroni corrected p-value threshold: 0.0083 = 0.05/6). Here, CD79A is linked to inflammatory bowel disease.