The present study demonstrates genetic variations of HTR3A rs1062613, SLC6A4 5-HTTLPR, COMT (rs4680, rs6269), and ADRA1D rs1556832, and TNFSF15 rs4263839 may contribute to a multigenic risk profile for IBS diagnosis and symptom burden. The gene discussed is TNFSF15; the disease is irritable bowel syndrome.