Computed tomographic colonography in subjects with positive faecal occult blood test refusing optical colonoscopy

Refusal of colonoscopy is a drawback of colorectal cancer screening programmes based on faecal occult blood test. Computed-tomographic-colonography is generally more accepted than colonoscopy.

To compare adherence to computed-tomographic-colonography and second-invitation colonoscopy in subjects with positive faecal test refusing colonoscopy.

We performed a prospective study in 198 subjects with positive faecal test who refused first referral to colonoscopy in one endoscopy service of the Florence screening programme. Subjects were randomly invited to computed-tomographic-colonography (n = 100) or re-invited to colonoscopy (n = 98). Mail invitation was followed by a questionnaire administered by phone. Computed-tomographic-colonography findings were verified with colonoscopy.

32 subjects could not be reached, 71 (35.9%) had undergone colonoscopy on their own; 4 were excluded for contraindications; 30/48 (62.5%) in the computed-tomographic-colonography arm and 11/43 (25.6%) in the colonoscopy arm accepted the proposed examinations (p < 0.001). Four advanced adenomas and 1 cancer were found in the 28 subjects who ultimately underwent computed-tomographic-colonography and 2 advanced adenomas and 2 cancers in the 9 subjects who ultimately underwent second-invitation colonoscopy.

Subjects with positive faecal occult blood test refusing colonoscopy show a higher adherence to computed-tomographic-colonography than to second invitation colonoscopy.