Specific acute colonic disorders.

This article reviews a variety of specific colonic disorders that may have been an acute clinical presentation. Less common causes of colonic obstruction include volvulus, intussusception, and hernias. Nonobstructive colonic dilatation is most often due to pseudo-obstructions and toxic megacolon. Several miscellaneous disorders discussed include colonic perforation, complications of leukemia that may affect the colon, and pseudomembranous colitis. The pathogenesis and clinical aspects of these disorders are reviewed, but the radiologic features are emphasized.