The impact of incomplete colonoscopies: a single-centre retrospective study

Screening for colorectal cancer reduces mortality by enabling early detection. In Quebec, follow-up within 60 days after an incomplete colonoscopy is recommended. In this study, we sought to assess the impact of delays in follow-up on patient outcomes.

In this retrospective study, we included adults who underwent a colonoscopy following a positive immunochemical fecal occult blood test at the Centre intégré universitaire de santé et de services sociaux de l'Estrie-Centre hospitalier de l'université de Sherbrooke between Jan. 1, 2013, and Dec. 31, 2015. We verified colonoscopy adequacy and guideline adherence. We classified advanced polyps and colorectal cancer as clinically significant lesions (CSLs) to assess the clinical impact of incomplete or missing follow-up colonoscopies.

In 89 cases of incomplete colonoscopies, inadequate bowel preparation was the leading cause of exam interruption (61.8%). A total of 57 patients had a subsequent follow-up, and 23 colonoscopies were completed within the 60-day time frame. Six CSLs, including advanced polyps and cancer, were detected within the recommended 60-day time frame, and 4 were identified after 60 days. We found a statistically significant difference in the rates of colorectal cancer diagnosis (p < 0.001), the need for surgery (p < 0.02), and death (p < 0.001) between patients who had a complete colonoscopy diagnostic process and those who did not.

The poorer prognosis associated with patients who had a delayed or missing follow-up highlights the importance of respecting provincial guidelines concerning follow-up after incomplete colonoscopies.