The role of psychosocial factors in the understanding of inflammatory bowel disease (IBD) has been a major area of clinical interest and psychosomatic research. This paper explores the scientific basis for the following contentions: (1) psychosocial factors such as stressful life events are associated with symptom onset and exacerbation; (2) research in brain‐gut peptides and the new fields of psychoimmunology and psychoneuroendocrinology may establish the physiological basis for this clinical observation; (3) while there is no proof for the psychosomatic specificity hypothesis, certain psychodynamic observations, particularly conflicts relating to real or threatened loss and extreme dependency with parental figures, are frequently observed; (4) there is a higher prevalence of psychiatric disorders (particularly depression) among patients with Crohn's disease; (5) the psychosocial impact of these disorders may be considerable, yet patient adjustment and perceived quality of life is generally favourable.