The surgical removal of a diseased portion of the distal colon or proximal rectum with formation of an end colostomy, accompanied by over-sewing of the distal colonic or rectal remnant. This procedure may be the first stage of a two-part operation, in which at a later date, the colostomy and the over-sewn remnant are reconnected. The Hartmann procedure is most often employed in debilitated patients or in emergent circumstances in which primary anastomosis or complete distal segment excision would not be appropriate.