High rates of irritable bowel syndrome (IBS) symptoms have been reported in individuals diagnosed with anxiety and depressive disorders. However, most studies have investigated these relations in a single disorder, rather than a heterogeneous group of patients, thereby not allowing for comparisons across anxiety disorders and depression, or for considering the effects of comorbidity. Thus, the present study investigated the symptoms of IBS in a diverse group of patients (N=357) by administering questionnaires and a diagnostic interview. A high frequency of IBS symptoms was found in patients with panic disorder, generalized anxiety disorder, and major depressive disorder. However, the frequency of IBS symptoms in patients with social anxiety disorder, specific phobia, and obsessive-compulsive disorder was comparable to rates found in community samples. In addition, anxiety sensitivity and illness attitudes and intrusiveness were predictive of elevated IBS symptomatology. Together, these findings emphasize the role physiological symptoms of anxiety and worry in the co-occurrence of the anxiety disorders and IBS.