Crohn's Disease is a chronic inflammatory bowel condition characterised by inflammation that can affect any part of the gastrointestinal tract from the mouth to the anus. Unlike Ulcerative Colitis which is confined to the colon and its innermost lining, Crohn's inflammation penetrates through the full thickness of the gut wall and can occur in patches with healthy tissue in between, a pattern called skip lesions. This transmural inflammation is what makes Crohn's particularly serious, it can lead to strictures, fistulas, abscesses, and perforation when uncontrolled. But Crohn's is not simply a gut condition that needs to be suppressed. It is an immune condition operating in a gut environment that has become incompatible with immune tolerance and that environment is identifiable, measurable, and addressable.