Influencing factors of different bowel preparation regimens on the quality of colonoscopy

Objective To explore the influencing factors of different bowel preparation before colonoscopy on the intestinal cleanliness and polyp detection rate. Methods From March to August in 2018, at the Center of Endoscopy of Huashan Hospital Affiliated to Fudan University, the patients who underwent colonoscopy were selected and their general data of bowel preparation regimens were collected. Self-factors of the patients, different bowel preparation regimens, bowel preparation quality and polyp detection rate were observed. The quality of bowel preparation was evaluated by Boston bowel preparation scale (BBPS). T test, and analysis of variance and chi-square test were used for statistical analysis. Results Among 1 008 patients who underwent colonoscopy, there were 506 males and 502 females, and average age was (57.3±13.7) years. There were statistically significant differences in BBPS score of patients with different body mass index (BMI), Parkinson disease and history of abdominal surgery (F=3.319, t=-2.060 and -2.544; all P<0.05). The BBPS score of patients with three-day low residue diet before examination was higher than that of those without preparation before examination (6.04±2.50 vs. 5.54±2.73), and the difference was statistically significant (t=2.514, P=0.010). The BBPS scores of 2 000 mL polyethylene glycol electrolyte lavage solution (PEG) taken once, 2 000 mL PEG taken separately, 3 000 mL PEG taken once and 3 000 mL PEG taken separately were 5.06±2.88, 6.11±2.44, 5.94±2.32 and 6.10±2.47, respectively, and the difference was statistically significant (F=7.242, P<0.01). There were significant differences in polyp detection rates among the patients with different age, gender, BMI, and with history of constipation, hypertension and diabetes mellitus (χ2=33.170, 8.489, 12.024, 4.034, 26.790, 10.381; all P<0.05). The polyp detection rate of patients with oral methyl silicone oil was higher than that of patients without oral methyl silicone oil (52.6%, 30/57 vs. 29.7%, 221/744), and the difference was statistically significant (χ2=12.934, P<0.01). Age (odds ratio (OR)=1.328, 95% confidence interval (CI) 1.162 to 1.517) and BMI (OR=1.412, 95%CI1.115 to 1.787) were independent risk factors for polyp detection rate. Conclusions Parkinson disease, history of abdominal surgery and BMI are the related factors affecting the quality of bowel preparation before colonoscopy. Age and BMI are independent risk factors for polyp detection rate. Key words: Colonoscopes; Polyethylene glycols; Bowel preparation; Simethicone