A review of the pathogenesis of IBS indicates the involvement of factors such as abnormal gastrointestinal motility, visceral hypersensitivity, brain-gut axis interactions, intestinal flora disorders and metabolic abnormalities, gastrointestinal infection and inflammation, psychophysiological factors and central nervous system disorders, food factors, genetics and gene polymorphisms.[5] Therefore, we inferred that HLA-A and HLA-B genes may be additional factors involved in the pathogenesis of IBS. Here, HLA-B is linked to irritable bowel syndrome.