Irritable bowel syndrome (IBS) is an extremely common chronic intestinal disorder characterized by recurrent abdominal pain and altered bowel habits, significantly impacting patients' quality of life. The etiology of IBS remains incompletely understood. Research has identified low-grade intestinal inflammation and immune activation, primarily manifested as an imbalance between pro-inflammatory and anti-inflammatory cytokines, as key pathogenic mechanisms in IBS. Among these, interleukin-6 (IL-6), a core pro-inflammatory cytokine, is significantly elevated in IBS patients. IL-6 contributes to the pathogenesis of IBS through various mechanisms, including altering individual susceptibility to IBS, promoting gastrointestinal motility and secretion, activating the hypothalamic-pituitary-adrenal axis, inducing visceral hypersensitivity, and impairing intestinal mucosal barrier function. Furthermore, IL-6 levels are closely associated with the severity of IBS symptoms. This review summarizes the role and mechanisms of IL-6 in IBS, aiming to provide insights and references for clinicians and researchers investigating the etiology of IBS.