A collection of symptoms and signs resulting from the gut’s inability to absorb one or more nutrients adequately. Rather than a single disease, it describes the clinical picture shared by coeliac disease, pancreatic insufficiency, short bowel syndrome, and other disorders: diarrhoea, steatorrhoea with pale bulky stools, weight loss, anaemia, and deficiencies of fat-soluble vitamins and minerals. Doctors use the term when the pattern of malabsorption is clear but the precise cause is still under investigation. Management combines treating the underlying disorder with nutritional rehabilitation, including tailored diets, vitamin and mineral supplements, and sometimes specialised formulas to restore nutritional status.