Risk Factors for Inadequate Bowel Preparation During Colonoscopy in Nigerian Patients

Background The past few decades have witnessed the introduction of various innovative technologies into colon study by colonoscopy. A well-prepared bowel is crucial to their effective utilization. An inadequate bowel preparation during colonoscopy is associated with increased technical difficulties, enhanced risks of perforation, longer examination durations, reduced adenoma detection rates, and additional costs related to repeated colonoscopies. There is a paucity of literature from Africa on the multiple patient factors that affect the quality of bowel preparation; hence, the need to identify patients at risk for inadequate bowel preparation to allow for more diligence in this special group. Aim To study the risk factors of inadequate bowel preparation for colonoscopy and identify the group of patients who need intensified preparation in a Nigerian population. Methods A case-control study of consecutive patients undergoing colonoscopy in an open access/referral-based multi-disciplinary endoscopy facility in Port Harcourt metropolis, Nigeria from March 2014 to November 2020. Consecutive adult patients who underwent colonoscopy with inadequate bowel preparation irrespective of the indication were retrospectively identified. Each case of inadequate bowel preparation while using a particular bowel preparation agent was matched with the next colon study with adequate bowel preparation (control) for the same agent in a 1:1 ratio. The variables collated were age, gender, literacy level, colonoscopy indication, medical history, bowel preparation agent, timing of endoscopy, and outcome. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 25 (IBM Corp., Armonk, NY). Results There were 143 cases of inadequate bowel preparation during colonoscopy included in the study with an equal number of control (cases of adequate bowel preparation). The age of patients ranged from 24 years to 92 years. Bleeding per rectum - 122(42.7%), and screening for colorectal cancer - 67(23.4%), were the leading indications for colonoscopy in study patients. Bivariate analysis of cases and controls revealed significant difference in educational status, comorbidity of hypertension, and constipation (p < 0.01, p = 0.082, p = 0.143, respectively). In the multivariate analysis of risk factors, the odds ratio (OR) for secondary level of education and below was 2.54 (95% confidence interval CI 1.50-4.30; p = 0.001); hypertension - OR 1.64 (95% CI 0.98-2.73; p = 0.058); constipation - OR 1.27 (95% CI 0.52-3.10; p = 0.598). Conclusion The educational status of patients is a strong risk factor associated with inadequate bowel preparation for colonoscopy in this Nigerian population. There is a need for effective patient education especially for patients with a low literacy level.