An interconnection between psychological and gastrointestinal (GI) functioning has long been recognized, incorporating multiple mechanisms and considering bidirectional processes. However, exciting discoveries regarding the role of stress and depression in etiology and disease course have shed new light on the understanding of biopsychosocial processes in chronic GI conditions. This article provides an introduction to GI tract functioning, GI disorders, and stress mechanisms in the gut, followed by an overview and discussion of the psychosocial impact of these disorders, the role of stress and mental comorbidity in GI disorders, and the current knowledge regarding psychological interventions for GI disorders.