**12. New directions – Noncathartic bowel preparations**

One new hope for the future is for patients to undergo CTC without laxatives or the need for a purgative bowel preparation. Patients would only need to ingest fecal tagging agents such as Gastroview or barium, one to two days before the test [142]. A pilot study using a noncathartic bowel preparation (low fiber diet and fecal tagging) had disappointing results demonstrating that the lack of bowel cleansing made the examination subjectively harder to interpret and likely missed significant polyps [143]. A subsequent study however using a noncathartic bowel preparation was performed in a high risk population [144]. Subjects in‐ gested 21.6 g of barium in nine divided doses. This study demonstrated that the sensitivity of CTC using a non-cathartic bowel preparation for polyps greater than 9 mm was over 90% [144].

Limited or non-cathartic bowel preparations may be especially useful in the frail or elderly patient. In a prospective study, 67 elderly patients with reduced functional status under‐ went CTC using a limited bowel preparation consisting of a low-residue diet for 3 days, 1 L of 2% oral diatrizoatemeglumine (Gastrografin) 24 hours before CTC, and 1 L of 2% oral Gastrografin over the 2 hours immediately before CTC [145]. No cathartic preparation was administered. All colonic segments were graded from 1 to 5 for image quality (1, unreada‐ ble; 2, poor; 3, equivocal; 4, good; 5, excellent). Overall image quality was rated good or ex‐ cellent in 84% of the colonic segments. Colonic abnormalities were identified in 12 patients (18%), including four colonic tumors, two polyps, and seven colonic strictures [145].


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Sep-Oct;38[5]:564-7. PubMed PMID: WOS:A1992JT93000008.

502-13. PubMed PMID: WOS:000169145500007.

127[2]:452-6. PubMed PMID: WOS:000223431200016.

PMID: WOS:A1981MU13100013.

PMID: WOS:A1987K557000012.

WOS:A1997WA90500005.

WOS:A1996TN35200034.

000251437300005.

000283295300024.

000237759300004.

**Table 1.** Sensitivity and specificity of polyps detected by CTC.
