While psychological factors and the brain-gut axis heavily influence irritable bowel syndrome (IBS), modern medical consensus views it as a biopsychosocial disorder involving concrete physiological mechanisms like gut motility, visceral hypersensitivity, and microbiome alterations, rather than a purely psychosomatic illness.
The claim that IBS is a psychosomatic disorder is contested by contemporary medical literature. While older and psychological perspectives (e.g., papers 0, 1, 5, 6) emphasize the strong influence of stress, brain-gut interactions, and psychiatric comorbidity, modern physiological studies (e.g., papers 2, 3, 7, 9) demonstrate that IBS is driven by distinct somatic pathophysiology such as gut dysbiosis, visceral hypersensitivity, and immune activation. Consequently, experts classify IBS as a biopsychosocial disorder of the gut-brain interaction rather than a purely psychosomatic condition.