Introduction NICE guidelines imply that most patients require WCI for bowel cancer diagnosis. This and fear of missing cancer in outpatients is the major reason for over investigation of patients with bowel symptoms. Greater understanding of the way proximal bowel cancer presents is required.

Method Retrospective cohort analysis using clinical data collected prospectively for 22 years (1986 to 2007) in a colorectal outpatient clinic in Portsmouth. 29005 patients were analysed to determine symptom combinations, signs and IDA according to site of the colon. Missed cancers were identified from referral back to clinic, local audit and comparison with the regional Cancer Registry.

Results 1626 patients had cancer of which 1585 presented with one of three bowel symptoms (change in bowel habit, rectal bleeding or abdominal pain). Only 16% (258/1585) were cancers proximal to the sigmoid colon, of which 44% (113/258) presented with symptoms alone (no IDA, no mass), 223 (113/25191) patients would need WCI to diagnose one proximal cancer in this group. Diagnostic yield of proximal cancer in patients <60 years without a mass or IDA was 0.09% (11/11828).

Conclusion Patients without mandatory reasons for immediate WCI after a normal flexible sigmoidoscopy (particularly those aged <60 years) should be offered a treat watch and wait diagnostic strategy rather than immediate WCI. NICE guidelines may be encouraging over investigation of patients by WCI.

Disclosure of interest None Declared.