Symptoms associated with finding colorectal cancer during colonoscopy

Patients with an increased risk of having colorectal cancer (CRC) should have priority on the colonoscopy list.

To investigate whether presenting symptoms of patients referred for colonoscopy could help in identifying patients with an increased risk of CRC.

Between February 2007 and November 2010, random outpatients referred for colonoscopy were asked to fill out a questionnaire with respect to symptoms for which the colonoscopy was performed. Informed consent was obtained to review the colonoscopy and histology reports. Multivariate logistic regression was performed to identify predictors for CRC.

In total, 1458 (21%) patients returned the questionnaire, of whom 925 (63.4%) had undergone previous sigmoidoscopy or colonoscopy. CRC was detected in 41 patients (2.8%). Age over 50 years [adjusted odds ratio (aOR) 3.00; 95% confidence interval (CI) 1.30-6.91] and presenting symptoms of rectal blood loss (aOR 4.62; 95% CI 2.31-9.22) and a change in bowel habits (aOR 3.33; 95% CI 1.50-7.40) were associated independently with an increased risk of finding CRC. Previous sigmoidoscopy or colonoscopy (aOR 0.24; 95% CI 0.12-0.49) and fatigue as presenting symptoms (aOR 0.22; 95% CI 0.09-0.56) were associated with a decreased risk of CRC. Weight loss, self-reported anemia, and abdominal pain were not associated with CRC in this study.

Patients presenting with rectal blood loss, change in bowel habits, and those older than 50 years of age have an increased risk of a finding of CRC during colonoscopy. We recommend that these risk groups should be prioritized on the colonoscopy list over patients who have undergone a previous endoscopy or who are presenting with fatigue.