Observational StudyEvaluation of Stool Tagging for Improved Patient Compliance

Computed tomography (CT) colonography has gained widespread multi-disciplinary interest as an evolving noninvasive colorectal screening examination, with the potential of improved patient compliance. The investigator's prior work demonstrated that the bowel preparation was the least tolerable aspect of colorectal evaluation when compared to the CT colonography and optical colonoscopy procedures. Stool tagging could provide a more gentle and efficient bowel preparation, with fewer false positives due to retained stool-mimicking polyps.

The researchers hypothesize that image quality and patient preference will vary with stool tagging concentration and dosing schedule. The researchers propose to evaluate specific stool tagging protocols with the following aims:

AIM 1: Perform a randomized trial of three specific stool tagging protocols using barium and iodine at CT colonography in a well-characterized cohort of patients undergoing colorectal evaluation.

AIM 2: Analyze the CT colonography and optical colonoscopy data to assess differences across stool tagging protocols for the outcome measures of patient preference, image quality in the presence of tagging, and diagnostic reader performance.

The researchers will use specific variations in stool tagging techniques to determine the best image quality of CT data (e.g., homogenous tagging of fluid and stool), and highest patient acceptability, as well as evaluate the adequacy of preparation for same-day colonoscopy. Diagnostic reader performance will focus on the accuracy for detecting all neoplastic lesions including colon cancers, adenomatous polyps, sessile adenomas and flat adenomas. Most importantly, these results will help inform the design of a larger trial of an optimized CT colonography technique in a community setting.