The relationship between schizophrenia and irritable bowel syndrome (IBS)

Irritable bowel syndrome (IBS) has been reported in 10-22% of adults. Amongst patients seeking medical attention for IBS 70-90% may have psychiatric co-morbidity, most commonly major depression. In contrast, few studies have looked at the prevalence of IBS in psychiatric patients. To our knowledge, there are no studies assessing the prevalence of IBS in patients with schizophrenia. Using a semistructured clinical interview to study the prevalence of IBS, we compared 47 patients with schizophrenia to an age-matched control group (n = 40) of patients who were seeking treatment in a primary care physicians office for other medical illnesses. IBS was diagnosed according to the criteria of Drossman et al. Nineteen percent (n = 9) of the patients with schizophrenia met criteria for IBS in contrast to 2.5% (n = 1) of the control group (p = 0.012). Schizophrenic patients seldom complain of gastrointestinal symptoms until specifically asked. Therefore, it may be important to inquire about gastrointestinal symptoms prior to initiating pharmacotherapy in order to differentiate side effects from a prior existing condition. Prospective studies should address the question whether remission of psychosis leads to improvement or resolution of IBS.