Defining surgical therapy for pseudomembranous colitis with toxic megacolon

Background: Pseudomembranous colitis has increased in incidence and severity over the past 10 years. Toxic megacolon is a rare but reported presentation of severe pseudomembranous colitis. This article reviews the reported cases of Clostridium difficile with toxic megacolon in the literature and introduces an additional case that underscores the importance of early diagnosis in guiding appropriate therapy. Methods: A systematic review of the literature was performed to identify previous reports of pseudomembranous colitis presenting with toxic megacolon, and the outcomes of each of these cases was analyzed. The review was focused on atypical presentations in immunocompromised patients. Results: Seventeen cases of C. difficile colitis presenting as toxic megacolon were identified. The overall mortality rate was 50% (9/18). Fifteen patients underwent surgery with an associated mortality rate of 50%. Thirteen patients had a subtotal colectomy. Seven of the patients (39%) were taking immunosuppressant medications, and 5 (28%) patients presented with atypical symptoms. Three (76%) of those were immunosuppressed. In several cases, failure to make an early diagnosis of C. difficile colitis resulted in a worse outcome because appropriate therapy was delayed. Conclusions: Toxic megacolon is well-established as an unusual presentation of C. difficile colitis. These patients are less likely to present with typical symptoms such as diarrhea or typical risk factors like recent administration of antibiotics, so diagnosis can be a challenge. A patient presenting with toxic megacolon without a history of inflammatory bowel disease should be assumed to have C. difficile colitis until proven otherwise, and medical or surgical therapy administered accordingly.