Definition of Toxic Megacolon

Toxic megacolon is an enlarged, inflamed colon. Inflammation damages the tissues of the colon and produces chemicals that are toxic to the colon, actually killing the colonic tissue, and eventually leading to its enlargement. If released into the blood, the chemicals also can be toxic to the rest of the body. The concern is that the colon will rupture or that bacteria within the colon will enter the blood through the damaged colonic tissue and give rise to sepsis. Several common conditions that cause toxic megacolon include colonic infections, ulcerative colitis, and ischemia (lack of blood flow).