Distinct pain profiles across irritable bowel syndrome subtypes: results from the Rome Foundation Global Epidemiology Study

Abdominal pain is the hallmark symptom of irritable bowel syndrome (IBS), yet its clinical expression varies considerably across subtypes. Despite this, few large-scale studies have compared pain features across all Rome IV-defined IBS subtypes. We aimed to delineate differences in abdominal pain patterns across IBS subtypes and evaluate the contribution of psychological comorbidities, extra-intestinal symptoms, and intermediate factors associated with psychological distress. Data were derived from the internet survey of the Rome Foundation Global Epidemiology Study, encompassing 54,127 participants from 26 countries, including 2195 IBS patients [712 constipation-predominant IBS (IBS-C), 629 diarrhea-predominant IBS (IBS-D), 712 mixed-type IBS (IBS-M), 142 unclassified-IBS (IBS-U)]. Clinical, dietary, and psychological parameters were assessed using validated questionnaires. Mediation analysis examined whether the association between IBS and psychological distress was attenuated after inclusion of illness perception, food avoidance, and work/activity impairment. IBS-C patients exhibited longer, more severe, and widespread pain, often radiating to the back and associated with greater analgesic use, while pain in IBS-D patients was linked to stool frequency and consistency changes. IBS-C patients reported greater dissatisfaction with bowel function, IBS-U patients frequently identified abdominal pain and bloating/distention as their most bothersome symptom. Psychological distress and somatic symptom burden were prevalent across all subtypes (69-78% and mean scores of 8.3-95, respectively). Mediation analyses revealed partial indirect associations of concerns about bowel function, embarrassment, and work/activity-related impairment, but not food avoidance. IBS subtypes demonstrate distinct pain and psychosocial profiles. Psychological burden is partly accounted for by illness perceptions and work/activity impairment, emphasizing importance of personalized, multimodal management strategies.