The large bowel accounts for roughly half of all episodes of gastrointestinal ischemia. Three major manifestations of ischemic injury to the colon can be distinguished: massive bowel infarction (gangrenous colitis), hemorrhagic enterocolitis, and ischemic colitis (nongangrenous colitis). Ischemic colitis, usually due to subacute colonic ischemia, is the most common form. The disease can be reversible or irreversible. It affects mainly elderly, but younger patients can also show features of ischemic colitis in particular situations. It occurs on the mucosal side (ulcero-inflammatory pattern) or transmural (cobblestoning and strictures). Histology shows a characteristic picture with variable cell necrosis, minimal inflammation, and hyalinization of the stroma.