Ulcerative Colitis

In a nutshell

UC is continuous, mucosal inflammation that always starts at the rectum and spreads proximally, confined to the colon. That explains bloody diarrhoea and tenesmus, and why severe mucosal inflammation can still cause toxic megacolon despite being 'superficial'. Colectomy is curative because disease never extends beyond the colon.

Classic presentation

Relapsing bloody diarrhoea with mucus, urgency and tenesmus, sometimes with an acute severe flare of frequent bloody stools, fever and tachycardia.

Key points

• 1Disease is continuous, always starts at the rectum, and is confined to mucosa/submucosa: the opposite of Crohn's transmural skip lesions.