Toxic megacolon.

Toxic megacolon is a clinical entity characterized by fever, tachycardia, and other toxic symptoms and having as its distinguishing feature dilation of a part or all of the colon. It is the result of the acute onset or exacerbation of ulcerative colitis or, less often, granulomatous enterocolitis, amebiasis, or pseudomembranous colitis. The primary inflammatory disease must be accurately identified, and malignant tumors, such as adenocarcinoma and lymphoma, capable of producing clinical findings similar to those of toxic megacolon must be excluded. Aggressive supportive therapy is essential, and early operation to remove the colon is usually necessary to avoid death as a result of this dreaded complication.