Colonoscopy outcomes following positive FIT and gFOBT: a retrospective study at the Princess Margaret Hospital in Nassau, Bahamas (2023–2025)
Christa Lyons, Eunice Ong’era, Eugene CooperObjectives
To examine colonoscopy findings in patients with a positive faecal immunochemical test (FIT) or guaiac-based faecal occult blood test (gFOBT) and to compare the yield of clinically significant lesions following each test.
Design
Retrospective cross-sectional analysis.
Setting
Gastroenterology Specialty Clinic at the tertiary public referral hospital, Princess Margaret Hospital, in Nassau, Bahamas.
Participants
Patients referred for colonoscopy following a positive FIT or gFOBT between 2023 and 2025.
Interventions
Diagnostic colonoscopy following a positive stool-based colorectal cancer (CRC) screening test.
Main outcome measures
Detection of clinically significant lesions, defined as histologically confirmed pre-cancerous lesions or cancerous lesions.
Results
75 patients were included; most were women, older and had a positive gFOBT. Three colonoscopies in the gFOBT-positive group were incomplete due to inadequate bowel preparation or caecal intubation failure. Among completed procedures, common findings included masses, polyps, diverticulosis and haemorrhoids. Clinically significant lesions were identified in 31 patients (41.3%; 95% CI 30.2% to 52.4%). These lesions were identified in 14 of 23 patients with a positive FIT (positive predictive value (PPV) 60.9%; 95% CI 38.5% to 80.3%) and 17 of 49 patients with a positive gFOBT (PPV 34.7%; 95% CI 21.7% to 49.6%). Patients with a positive FIT had higher odds of a clinically significant lesion on colonoscopy than those with a positive gFOBT (OR 2.93; 95% CI 1.01 to 8.47; p=0.044).
Conclusions
Positive stool-based screening tests were associated with diverse colonoscopic findings and a substantial burden of clinically significant lesions. Among test-positive individuals, FIT was associated with significantly higher odds of detecting a clinically significant lesion than gFOBT. The higher yield observed following FIT supports its consideration in optimising CRC screening strategies in The Bahamas.