Crohn's disease is a chronic inflammatory bowel disease that can affect any part of the gastrointestinal tract from mouth to anus, although the ileum, colon and perineum are most commonly involved. It is characterized by transmural granulomatous inflammation. Crohn's disease is thought to result from a complex interplay of multiple genetic and environmental factors. Alterations in the microbiota signature with reduced microbiota diversity are observed. Diarrhoea, abdominal pain, fatigue, weight loss and fever are hallmarks of Crohn's disease.