	Non-granulomatous relapsing and remitting continuous inflammation in colonic mucosa
Etiology	Age of onset 15-30 years.
Epidemiology
Clinical presentation	PR bleeding axial/peripheral arthritis, erythema nodosum, pyoderma gangrenosum, anal skin tags, fistulae (in any location), osteopenia, uveitis/episcleritis, anaemia.
Pathogenesis
Diagnostic investigations	stool culture, faecal calprotectin Colonoscopy + biopsy: inflammatory infiltrate; ↓ goblet cells; mucosal ulcers; crypt abscesses; backwash ileitis
Management	See below

inducing remission

mild to moderate first presentation

first line: IV corticosteroid (ciclosporin possible as alternative)
second line: ADD ciclosporin to IV corticosteroid
- infliximab if ciclosporin contraindicated