DCBE, Double-Contrast Barium Enema

If colonoscopy is not available or feasible, DCBE alone or together with flexible sigmoidoscopy are acceptable alternatives. DCBE, double-contrast barium enema FOBT, fecal occult blood testing. 

CTC in symptomatic patients is to be considered when colonoscopy can not be completed or carried out this may occur due to mechanical hindrance such as pelvic adhesions, in cases of high risk of perforation as in complicated diverticular disease, when there is an obstruction due to cancer or extracolonic diseases, when the cecum cannot be reached in extreme dolicocolon conditions, or in patients with poor tolerance to colonoscopy in whom heavy sedation may be dangerous (elderly patients or patients with severe co-morbidity). Such indications are similar to those of double contrast barium enema (DCBE) however, CTC has been shown to be both more accurate and better tolerated than DCBE, and should be used preferentially whenever available (Rocket et al. 2005 Taylor et al. 2005 Taylor et al. 2006). Furthermore, in cases of obstructing colonic cancer, CTC is a valuable tool, as it can be conveniently performed at the time of a contrast-enhanced abdominal CT scan for staging purposes to detect synchronous colorectal carcinomas, metas-... 

The role of CT colonography has been evaluated specifically in this patient population. Incomplete colonoscopies secondary to post-operative strictures and rigid mesentery have been reported. In 2002, Gollub et al. reported a conventional colonoscopy failure rate of 4%-29% in post-operative or post-radiotherapy patients (Gollub et al. 2002). These patients would undergo a double contrast barium enema for complete evaluation of the colon. As discussed, CTC sensitivity for polyp detection is greater than DCBE and thus makes it a superior surveillance tool in this subset of patients. 

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