Importance of Bowel Habits in Predicting Inadequate Bowel Preparation: A Prospective Observational Study.

OBJECTIVES: Inadequate bowel preparation (BP) negatively affects the efficacy and quality of colonoscopy. Although constipation has already been reported as one of the most important predictors of inadequate BP, there is limited information on the relation between inadequate BP and bowel habits including constipation-related symptoms, medications, and severity of constipation. METHODS: This single-center, prospective observational study was conducted between August 2019 and May 2020. All participants answered questionnaires regarding personal bowel habits and received low-volume polyethylene glycol plus ascorbic acid for outpatient colonoscopy. Severity of constipation was evaluated by constipation scoring system. Bowel preparation cleansing was evaluated using Boston Bowel Preparation Scale (BBPS). Potential predictors of inadequate BP were analyzed using multivariate logistic regression models. RESULTS: Overall, 1054 patients were enrolled, of which, 105 (10%) had inadequate BP (total BBPS ≤ 6 or any segmental BBPS < 2). The risk of inadequate BP increased with constipation severity (P = 0.01). Multivariate analysis showed that frequent straining (> 25% of defecations) (OR 2.09, 95% CI: 1.33-3.28) and chronic use of stimulant laxatives (OR 2.57, 95% CI: 1.59-4.17) were significant predictors of inadequate BP, among personal bowel habits. CONCLUSION: Frequent straining and chronic use of stimulant laxatives were predictors of inadequate BP. An intensified preparation regimen should be considered for severely constipated patients with straining and chronic use of stimulant laxatives.

Efficacy and tolerability of 1 L polyethylene glycol plus ascorbic acid with senna versus 2 L polyethylene glycol plus ascorbic acid for colonoscopic bowel preparation: Prospective, randomized, investigator-blinded trial.

OBJECTIVES: Low-volume polyethylene glycol plus ascorbic acid (PEG-Asc) reduces the dosage of colonoscopic bowel preparation (BP) solution, but is still poorly tolerated. Adding laxatives to the BP solution reduces the volume of fluid required, without affecting quality. This study aimed to compare 1 L PEG-Asc plus 24 mg senna (1L-PEG/AS) and conventional 2 L PEG-Asc (2L-PEG/A) regimens on BP quality and patient tolerability. METHODS: A single-center, randomized, investigator-blinded, noninferiority trial was performed between June and August 2022. Outpatients scheduled for colonoscopy were randomized (1:1) to the 1L-PEG/AS or 2L-PEG/A group. The Boston Bowel Preparation Scale (BBPS) was used to evaluate BP quality. Adverse events and tolerability were surveyed using questionnaires. RESULTS: Overall, 344 patients received 1L-PEG/AS or 2L-PEG/A regimens. The baseline characteristics and adverse events of the two groups were comparable. The 1L-PEG/AS group showed noninferior adequate BP rates compared with the 2L-PEG/A group (88% vs. 89%, P = 1.00); overall BBPS was 7.1 ± 1.5 and 7.2 ± 1.5, respectively (P = 0.39). Higher willingness to repeat the BP was observed in the 1L-PEG/AS group (85% vs. 62%, P < 0.01). CONCLUSIONS: The 1L-PEG/AS regimen was comparable to the 2L-PEG/A regimen in terms of BP adequacy, requiring lower BP solution volumes, with better patient tolerance. Thus, it may be a suitable alternative to the conventional BP solution for colonoscopy. The Japan Registry of Clinical Trials (jRCT1051220043).

Chronic constipation is negatively associated with colonic diverticula.

OBJECTIVES: Constipation has been considered the key risk factor for diverticulosis occurrence, but the underlying mechanism is unclear. We investigated the factors associated with diverticulosis, focusing on the association of constipation severity with the localization and number of diverticula. MATERIALS AND METHODS: We analyzed consecutive patients who underwent colonoscopy between March and December 2019. Chronic constipation was diagnosed as constipation meeting Rome IV criteria or as that requiring laxative therapy for more than 6 months. The degree of constipation was scored using the Constipation Scoring System (CSS). RESULTS: We assessed 1014 patients. Multivariate analysis revealed that age, alcohol consumption, and hypertension were positively associated with diverticulosis, whereas chronic constipation was negatively associated with diverticulosis (odds ratio [OR] = 0.74; 95% confidence interval [CI], 0.55-0.99). When assessed according to the location of diverticula, right-sided diverticula were significantly associated with a lower incidence of constipation (OR = 0.94; 95% CI, 0.89-0.98), whereas neither left-sided nor bilateral diverticula was associated with constipation. This negative association of diverticula with constipation was stronger in patients with a high CSS score. In stratified analysis, the number of diverticula decreased with increasing degree of constipation (p for trend <.01), and a high CSS score was associated with a decreased prevalence of ≥3 diverticula (OR = 0.64; 95% CI, 0.44-0.99). CONCLUSIONS: Chronic constipation was negatively associated with colonic diverticulosis. The association increased with the degree of constipation and was strong only in cases with right-sided diverticula and those with ≥3 diverticula.