Controlled clinical trials are lacking for patients with fulminant colitis who may not tolerate oral therapy. Administration of metronidazole intravenously or administration of vancomycin by nasogastric tube or rectal enema has been described in small case series (17-20). Intravenous administration of vancomycin is not recommended, because the drug is not excreted in the colon (17).
Management of Recurrent C. difficile Diarrhea
Despite successful initial treatment of CDAD, 15–20% of patients have recurrence of diarrhea in association with a positive stool test for C. difficile toxin. Symptomatic recurrence is rarely due to treatment failure or antimicrobial resistance to metronidazole or vancomycin. Approaches to management include conservative therapy (however, many patients are elderly and infirm and unable to tolerate diarrhea), therapy with specific anti–C. difficile antibiotics, the use of anion-binding resins, therapy with microorganisms (probiotics), and immunoglobulin therapy.
The most common therapy for recurrent C. difficile diarrhea is a second course of the same antibiotic used to treat the initial episode (12). In a large observational study in the United States, 92% of patients with recurrent CDAD responded successfully to a single repeated course of therapy, usually with metronidazole or vancomycin (14). There is evidence to suggest that patients with a history of recurrence have a high risk of further episodes of CDAD after antibiotic therapy is discontinued. There are no data to suggest that sequential episodes become progressively more severe or complicated (21). A variety of treatment schedules have been suggested for patients with multiple recurrences of C. difficile diarrhea. One approach is to give a prolonged course of vancomycin (or metronidazole) using a decreasing dosage schedule followed by pulse therapy (Table 4).
Cholestyramine, an anionexchange resin administered at a dose of 4 grams 3 or 4 times daily for 1 to 2 weeks, binds C. difficile toxins and may be used in conjunction with antibiotics to treat repeated relapses. Because cholestyramine may bind vancomycin as well as toxins, it should be taken at least 2 to 3 hours apart from the vancomycin.
Severe C. difficile Colitis
The incidence of fulminant C. difficile colitis has been reported to be 1.6–3.2% (22). Although recent precise figures from other centers are lacking, it is being recognized as an increasing cause of complications and death. The clinical syndrome of fulminant C. difficile colitis can be recognized with a proper knowledge of the spectrum of disease presentation.
A. Diarrhea: Although diarrhea is the hallmark of C. difficile colitis, it is not invariably present, and its absence may lead to diagnostic confusion. When diarrhea is absent, this appears to be secondary to severe colonic dysmotility. Even when present, diarrhea may be perceived to be a minor component of a nonspecific septic picture.
Reprinted with permission from BUMC Proceedings 1999; 12:249-250
Figure 1 . Digital radiograph from CT scan shows nodular haustal thickening in the transverse colon.
Reprinted with permission from BUMC Proceedings 1999; 12:249-250
Figure 2 . CT image of the upper abdomen confirms marked haustral thickening in the transverse colon.
Reprinted with permission from BUMC Proceedings 1999; 12:249-250
Figure 3 . CT image of the mid abdomen demonstrates marked thickening of the entire colon. Mild inflammatory changes are present in the pericolonic fat.
B. Severe Disease: Fulminant colitis is an unusual form of C. difficile infection, occurring in only 3% of patients but accounting for virtually all serious complications. Patients with more severe forms of the disease may present with or without diarrhea. When patients develop colitis localized to the cecum and right side of the colon, diarrhea may be minimal or absent. In the absence of diarrhea, the only clues to diagnosis may be systemic signs of toxicity (fever, tachycardia, leukocytosis, and/or volume depletion).