SUMMARYIschaemic lesions of the colon can be divided into gangrenous and non-gangrenous groups.In this paper 17 patients with non-gangrenous ischaemic colitis are reported; 16 of these occurred spontaneously and I followed an anterior resection of the rectum.The clinical and radiological findings are described. The lesions varied in extent and severity from a short segment of transient mucosal damage to a long permanent stricture.An early barium-enema examination is essential for the initial diagnosis. Repeat barium enemas are necessary to ascertain the final outcome. The radiological changes are at least partially reversible and even extensive strictures may show a marked improvement over a period of months.In this group five lesions were resected but none of the resections was performed during the acute phase. It is concluded that non-gangrenous lesions can usually be managed conservatively. The indications for surgical intervention are discussed.