Background <p>Mindsets are a recent framework for understanding the ways patients interpret their chronic health conditions. Despite the influence of the related concept of illness perceptions on physical and psychological outcomes in inflammatory bowel diseases (IBD), mindsets have yet to be examined in this illness. This study investigated the prevalence of illness and body mindsets in IBD patients and the relationship with physical and psychological outcomes.</p> Method <p>A total of 186 participants completed a cross-sectional survey assessing mindsets about illness and the body, along with the outcomes of physical symptoms, gastrointestinal symptom–specific anxiety, depression, anxiety, and stress. ANOVAs compared differences in outcomes between mindset categories.</p> Results <p>While “IBD is manageable” was the predominant illness mindset for 50.5% of participants, 28.5% viewed their condition as a catastrophe. For body mindsets, 38.2% viewed their body as responsive, while a similar proportion (37.6%) considered their body to be an adversary. Participants holding catastrophic and adversarial mindsets had significantly higher levels of symptom reporting, symptom-specific anxiety, and depression compared to those endorsing more adaptive illness and body mindsets.</p> Conclusion <p>Illness and body mindsets in IBD are characterized by different rates of symptom burden and mental health outcomes. The results highlight the varied prevalence of mindsets in and across health conditions and suggest there is a fine line between adversarial and responsive mindsets in IBD compared to other illnesses. As mindsets are malleable, these findings support the development of interventions to provide patients with tools to adapt their mindsets, to better manage their condition and improve quality of life.</p>