Toxic megacolon complicating Crohn's colitis.

Toxic megacolon complicating ulcerative colitis has been a well-recognized entity since its original description in 1950. The presence of toxic megacolon frequently has precluded a diagnosis of Crohn's colitis. Recent literature, however, has demonstrated that the incidence of toxic megacolon associated with Crohn's colitis (4.4-6.3%) may be higher than that in ulcerative colitis (1-2.5%). Differentiation between these two catastrophic forms of colitis is important in respect to prognosis and long-term results. Medical management of toxic megacolon may be initially successful in either type of colitis. Surgical intervention is indicated if the patient's condition does not improve within 48-72 hours. A subtotal colectomy with an ileostomy and mucous fistula is probably the treatment of choice for most of these extremely ill patients. The influence of the type of colitis on the results of subsequent management of the rectal stump remains unresolved.