Crohn's disease

Crohn's disease is a chronic, relapsing and remitting inflammatory disease affecting any area of the gastrointestinal tract. It is becoming increasingly prevalent in western Europe, the USA and China, with the highest age-standardized prevalent rates in Norway. It is associated with modifiable risk factors such as smoking and diet, and non-modifiable risk factors including gene variants; however, there is no specific method to prevent its onset or effect a cure. Patients often complain of diarrhoea and abdominal pain, but symptoms can occur intermittently for many years before diagnosis. Diagnosis is usually made with ileo-colonoscopy and imaging. The key features on biopsy samples are transmural inflammation with granulomas. Early diagnosis, and thus early treatment, is key to reducing the risk of complications developing, such as strictures and fistulae. Treatments are aimed at reducing the inflammatory burden in the gut and can include enteral nutrition, drug therapy or surgical management. Drug therapy can be monitored by symptoms, using non-invasive stool tests (faecal calprotectin, radiological imaging), or ileo-colonoscopy. Up to 75% of patients require operative management in their lifetime; however, new drug therapies are likely to be licenced in the coming years and these will increase the options available for non-operative management.