Toxic megacolon in ulcerative rectocolitis. Current trends in clinical evaluation, diagnosis and treatment.

Toxic megacolon is a clinical condition associated to high risk of colonic perforation, that significantly increases--even triplicates--the megacolon-related mortality when causing diffuse peritonitis. Abdominal and pelvic helical CT scan proved to be a fundamental diagnostic tool, in defining the colic dilatation and perforation. Conservative treatment is initially indicated in the event of toxic megacolon arising at the onset of a severe or toxic colitis. However it should be avoided when the toxic megacolon appears on corticosteroid therapy. Non operative management must not exceed 48 hours. The rationale of this strategy lies on the fact that early surgery is burdened by a mortality rate that, although moderate, is still higher than medical treatment. Nevertheless, successful conservative management does not exempt from surgery, which must be performed as soon as possible, in an elective setting, to prevent the recurrence of toxic megacolon. In emergency total colectomy and end ileostomy is the gold standard procedure. Bowel continuity will be restored, evaluating case by case, by performing an ileorectal anastomosis or proctectomy and ileoanal pouch anastomosis. Primary ileorectal anastomosis should be reserved to selected cases. In the elective setting, after proper therapy and regression of toxic megacolon, proctocolectomy and ileoanal pouch anastomosis is indicated.