Volume of fluid consumption during preparation for colonoscopy is possibly the single most important determinant of bowel preparation adequacy

Development and validation of a novel scoring system based on a nomogram for predicting inadequate bowel preparation

BACKGROUND AND AIMS

Adequate bowel preparation (BP) is crucial for the diagnosis of colorectal diseases. Identifying patients at risk of inadequate BP allows for targeted interventions and improved outcomes. We aimed to develop a model for predicting inadequate BP based on preparation-related factors.

METHODS

Adult outpatients scheduled for colonoscopy between May 2022 and October 2022 were enrolled. One set (N = 913) was used to develop and internally validate the predictive model. The primary predictive model was displayed as a nomogram and then modified into a novel scoring system, which was externally validated in an independent set (N = 177). Inadequate BP was defined as a Boston Bowel Preparedness Scale (BBPS) score of less than 2 for any colonic segment. The model was evaluated by the receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA).

RESULTS

Independent factors included in the prediction model were stool frequency ≤ 5 (15 points), preparation-to-colonoscopy interval ≥ 5 h (15 points), incomplete dosage (100 points), non-split dose (90 points), unrestricted diet (88 points), no additional water intake (15 points), and last stool appearance as an opaque liquid (0-80 points). The training set exhibited the following performance metrics for identifying BP failure: area under the curve (AUC) of 0.818, accuracy (ACC) of 0.818, positive likelihood ratio (PLR) of 2.397, negative likelihood ratio (NLR) of 0.162, positive predictive value (PPV) of 0.850, and negative predictive value (NPV) of 0.723. In the internal validation set, these metrics were 0.747, 0.776, 2.099, 0.278, 0.866, and 0.538, respectively. The external validation set showed values of 0.728, 0.757, 2.10, 0.247, 0.782, and 0.704, respectively, indicating strong discriminative ability. Calibration curves demonstrated close agreement, and DCA indicated superior clinical benefits at a threshold probability of 0.73 in the training cohort and 0.75 in the validation cohort for this model.

CONCLUSIONS

This novel scoring system was developed from a prospective study and externally validated in an independent set based on 7 easily accessible variables, demonstrating robust performance in predicting inadequate BP.

Lower Gastrointestinal Bleeding in the Emergency Department: High- Volume vs. Low-Volume Peg Bowel Preparation for Colonoscopy: A Randomized Trial

BACKGROUND

Lower Gastrointestinal Bleeding (LGIB) is a common cause of admission to the Emergency Department (ED). Early colonoscopy is the exam of choice for evaluating LGIB, and an adequate colon cleansing is essential. High-volume solution 4L-PEG is largely used, but it has some limitations. Low-volume solution 2L-PEG may improve patient's tolerability and compliance, reducing the time of administration and speeding up the exam.

PATIENTS AND METHODS

We conducted a randomized 1:1, prospective observational monocentric study in 228 patients (144M/84F) with LGIB. 121 (69M/52F) received the High-Volume, while 107 (75M/32F) received Low-Volume. They completed a "satisfaction questionnaire" (taste and smell, mood, time of taking, general experience). We collected the results of the Boston Bowel Preparation Scale (BBPS) and the final diagnosis. The study was retrospectively registered on clinicaltrial.gov with protocol number NCT0536 2227.

RESULTS

A mean value of BBPS 6,3 was achieved by both groups (p=0.57). Regarding smell, taste, mood and time of taking (1 to 5), we do not find any statistically differences. The overall satisfaction between the two preparations was 2.90 for low-volume compared to 3.17 for Highvolume (p=0.06). No side effects were reported. The proportion of patients without an evident source of bleeding was higher in High volume preparations compared to Low-volume (39% vs. 30%, respectively).

CONCLUSION

Low volume bowel preparation showed the same efficacy and tolerability with better satisfaction compared with high volume. Low-volume could represent an effective and more desirable preparation for patients in the ED.