This report reviews recent research on the psychosocial aspects of the functional gastrointestinal disorders (FGIDs). A review and evaluation of existing literature was conducted by a multidisciplinary committee of experts in this field. This report is a synopsis of a chapter published in the Rome III book. The committee reached consensus in finding considerable evidence supporting the association between psychological distress, childhood trauma and recent environmental stress, and several of the FGIDs but noted that this association is not specific to FGIDs. There is also considerable evidence that psychosocial variables are important determinants of the outcomes of global well-being, health-related quality of life, and health care seeking. In line with these descriptive findings, there is now increasing evidence that a number of psychological treatments and antidepressants are helpful in reducing symptoms and other consequences of the FGIDs in children and adults. The FGIDs are a result of complex interactions between biological, psychological, and social factors, and they can only be treated satisfactorily when all these factors are considered and addressed. Therefore, knowledge about the psychosocial aspects of FGIDs is fundamental and critical to the understanding, assessment, and treatment of these disorders. More extensive physician training is needed if these aspects of treatment are to be used effectively and widely in clinical practice.