Colorectal Cancer Detection by Colonoscopy in Population Aged 50–70 Years with Positive Fecal Occult Blood Test: A Retrospective Cohort Study, Rasi Salai Hospital, Sisaket province

Abstract

Colorectal cancer mortality is increasing in Thailand. Screening with the fecal immunochemical test (FIT) followed by colonoscopy for FIT-positive individuals is an effective strategy to reduce mortality; however, evidence on colonoscopy quality indicators in community hospitals remains limited. The objective was to estimate the adenoma detection rate (ADR) among FIT-positive adults undergoing colonoscopy and factors associated with polyp detection. The method conducted a retrospective cohort study of adults aged 50–70 years with positive FIT results who underwent colonoscopy at Rasisalai Hospital during 2023–2025. Data were extracted from medical records and colonoscopy reports, including demographics, body mass index, health behaviors, colonoscopy findings, histopathology, cancer stage, and bowel preparation quality assessed by the Aronchick Scale. Descriptive statistics and inferential analyses (Chi-square or Fisher’s exact test, t-test, and multivariable logistic regression) were performed. The results occurred among 365 FIT-positive patients; 51.8% were female, and the mean age was 60.8±6.4 years. Polyps were detected in 130 patients (35.6%), and adenomatous polyps were identified in 103 patients, yielding an ADR of 28.2%. Colorectal cancer was diagnosed in 4.4% of patients; more than half were early stage, and the most common tumor site was the sigmoid colon (38.8%). Adequate bowel preparation was achieved in 96.2% of procedures, the cecal intubation rate was 96.4%, and one perforation occurred (0.3%). Adequate preparation rates were not different between polyethylene glycol and sodium phosphate (97.3% vs. 95.4%; p = 0.36). In multivariable analysis, increasing age at adjusted OR = 1.09 (95% CI 1.05–1.14; p < 0.001) and alcohol consumption at adjusted OR = 1.69 (95% CI 1.00–2.86; p = 0.049) were associated with polyp detection, whereas BMI and smoking were not. The conclusions found that in FIT-positive adults undergoing colonoscopy in a community hospital, ADR was 28.2% and met the American Society for Gastrointestinal Endoscopy (ASGE)-recommended benchmark, with high cecal intubation and adequate bowel preparation rates and a very low complication rate. Increasing age and alcohol consumption were significant risk factors for polyp detection.