- Transient - 80%
- Acute fulminant & gangrenous
- Chronic segmental ulcerating (ischaemic stricture)
Occlusive - arterial embolism Non-occlusive - arterial thrombus
Commonest site is left colon - rectum to splenic flexure
Acute onset cramping abdo pains, urge to defaecate, bloody diarrhoea, usually improve within 48hr otherwise surgery