OBJECTIVE: Irritable bowel syndrome has no observable symptom markers and there is little that the medical profession can do to help sufferers. Psychotherapy, antidepressants and drugs aimed at the most problematic symptoms have been shown to have limited efficacy. In an attempt to help understand the illness better, and to suggest alternative forms of intervention, the study tested whether outcome might be influenced by patients' representation of their illness and by their coping strategies. METHOD: All members of the IBS Network (an independent charitable support network based in the UK) were invited to participate via their quarterly newsletter, and 209 completed questionnaires were returned. Participants completed the Illness Perception Questionnaire (IPQ), the COPE, and the Hospital Anxiety and Depression Scale (HADS), and rated their quality of life and their satisfaction with their health. RESULTS: The reporting of serious consequences was associated with lower quality of life and lower satisfaction with health, and with higher scores for anxiety and depression (p <.001). Weaker control beliefs were related to lower quality of life, lower satisfaction with health, and higher depression scores (p <.01). Lower illness scores were associated with more satisfaction with health (p <.01), but not with quality of life (p >.05). Psychological causal attribution of IBS was positively correlated with anxiety (p <.001) and depression (p <.01). Path analyses based on multiple linear regression demonstrated that (1) the reporting of serious consequences was a strong independent predictor of outcome; (2) coping mediated the link between representation and outcome; and (3) when predicting depression, coping strategies predicted coping independently of representation dimensions. CONCLUSIONS: The findings indicate that the illness representations of IBS sufferers can have significant implications for outcome. Therapeutic interventions based on illness representations may prove useful for treatment.