PTH-024 Obesity and colonoscopy: not so difficult after all? The experience of a bowel cancer screening unit

Introduction Obesity is a risk factor for the development of colorectal cancer (CRC).1 Colonoscopy in obese patients has been suggested to be more technically difficult,23 but variation in indication and age of patients, and operator technical ability may be confounding factors. The Bowel Cancer Screening Programme (BCSP) has a single indication for colonoscopy in a narrow age band (60–70 years) and the colonoscopists are of a proven standard, therefore studying data from this group of patients may avoid confounding factors and give a truer assessment of technical difficulty. Methods We compared measures of technical difficulty (quality of preparation; caecal intubation rate and time; sedation/analgesia dose; and patient tolerance) and findings (polyp and cancer detection) in the Taunton Faecal Occult Blood positive (FOB+ve) BCSP colonoscopy patients in 2008/9 (N=359, males 209, females 150) in relation to their BMI. Results BMI was known in 348, and was 15.7–58.3 (median 28.0). One hundred and eleven patients (31.8%) had BMI >30. Bowel preparation scores were not affected by BMI (Fisher9s Exact Test, p=0.62), nor were sedation and analgesia requirements (all comparisons obese vs non-obese, Fisher9s Exact Test or regression analysis). Comfort scores were similar (minimal or no discomfort 63% vs 68%, p=0.33). Overall caecal intubation rates were 96.3%, vs 97.4% (p=0.73). Caecal intubation time was not effected by BMI (r=0.022, p=0.68). Polyps were found in 210 (58.4%) patients and cancer in 43 (11.9%) in total. BMI did not affect the number of polyps found (p=0.33). There was no significant difference in the number of cancers identified in patients with a BMI>30 (14 of 97) compared to the others (29 of 208) (p=1.0). Conclusion Obesity does not impair the technical performance of colonoscopy in this population. There is a high rate of obesity in the FOB +ve BCSP population, but the effect of obesity on findings cannot be assessed by this study, since the proportion of obese patients in the overall population from which this group is drawn was not available. Nether-the-less this study suggests that obesity should not be a factor in deciding whether colonoscopy is an appropriate investigation to exclude CRC.