CT Colonography: Expect the Best, Get the Worst

Patients randomized to receive CT colonography versus colonoscopy reported higher rates of embarrassment, pain, and overall burden than they had expected before the procedure.


The first large randomized controlled trial of computed tomographic colonography (CTC) versus colonoscopy for colorectal cancer screening was recently conducted in the Netherlands (JW Gastroenterol Jan 6 2012). A higher rate of patients invited to undergo CTC versus colonoscopy actually underwent the test (34% vs. 22%). Detection of advanced neoplasia was higher with colonoscopy, but overall yield was equal after adjusting for higher adherence rates with CTC. Now, the same investigators report participants' expected and actual burdens of the two tests from preprocedure and postprocedure questionnaires.

The proposed preparation for CTC involved a noncathartic stool-labeling regimen, rather than purgation, as required for colonoscopy. The expected burden questionnaire was completed by 1199 CTC invitees (41%) and 2111 colonoscopy invitees (36%). The perceived (i.e., actual) burden questionnaire was completed by 79% of colonoscopy recipients and 82% of CTC recipients. In general, expected burdens of colonoscopy were lower than actual, whereas the opposite was true for CTC (see table).

More colonoscopy recipients than CTC recipients were hindered from normal activities on the day before the procedure, but fewer were hindered the day after. More colonoscopy than CTC recipients had trouble sleeping the night before the procedure, but fewer had trouble sleeping afterward. Abdominal complaints that increased from baseline occurred more often among CTC recipients than colonoscopy recipients (48% vs. 24%) but were more painful among the latter group. The most burdensome aspect was rated as bowel preparation by colonoscopy participants and as the actual procedure by CTC participants. Willingness to participate in the next round of screening was high for both groups: 93% for CTC and 96% for colonoscopy.

Citation(s):

de Wijkerslooth TR et al. Burden of colonoscopy compared to non-cathartic CT-colonography in a colorectal cancer screening programme: Randomised controlled trial. Gut 2011 December 23; [e-pub ahead of print].