Background: The irritable bowel syndrome (IBS) is a common clinical disorder, however, still poorly understood since the development of symptoms is strongly related to stress, anxiety and depression. Objectives: To review the literature in order to determine whether, in fact, there is the influence of stress and psychiatric comorbidity in the development, diagnosis and treatment for patients with IBS. Methods: The review was conducted by searching the database MedLine and Lilacs from 1990 to 2009 using the keywords “stress”, “behavior”, “psychiatry” and “irritable bowel syndrome”. Results: Were selected 38 articles that related irritable bowel syndrome to the individual reaction to stress and psychiatric comorbidity, including anxiety and depression. Discussion: The reactivity of the individual to stress and psychosocial factors play an important etiologic role, although not conclusive, and may interfere with intestinal functioning by altering its motility or spasm, reduction or increase in secretion and, finally, in irritation. It is necessary to develop a methodology for defining and measuring somatization to aid in clinical diagnosis and the inclusion of psychosocial factors related to the development and persistence of symptoms in the diagnostic criteria for IBS.