The comparison of the efficacy and tolerability of a one-day and a three-day diet at CT colonography: a prospective study
Authors: Meshcheryakov A. I. , Gurova N. Yu. , Kieva I. N. , Pugacheva O. G. , Dorodnykh D. V. , Makarova L. I. 
Published: August 2024

INTRODUCTION: CT colonography (CTC) is a highly accurate, minimally invasive method of intraluminal imaging of the colon using computed tomography. One of the main advantages of CTC compared to endoscopic colonoscopy is easier colon preparation due to the reduced volume of laxatives. However, colon cleansing, which includes dieting, is the most burdensome aspect of the entire procedure. At present, there is no consensus on the benefits of any dietary option for preparing the colon for CTC, and this issue requires further study.

OBJECTIVE: Comparison of the efficacy and tolerability of a one-day and a three-day diet at CT colonography (CTC).

MATERIAL AND METHODS: 107 patients were enrolled in this study. 55 patients adhered to a three-day diet (3DD) and 52 to a one-day diet (1DD). Each of six colonic segments was scored for residual fluid and stool using a 4-point scale (4 — absence; 3–1 — increasing fluid or stool). The quality of fecal tagging was assessed with fluid attenuation (HU values) and homogeneity (SD values). In addition, subjective severity of dieting and readiness to repeat the procedure were assessed.

Statistics: Comparison of groups after testing for normality of distribution was carried out using the Mann-Whitney U test for quantitative variables and using the Pearson χ2 test for categorical data. A p value <0.05 was considered statistically significant. Cohen’s kappa analysis was performed to assess interobserver agreement. All calculations were performed using statistical software Jamovi version 1.2.27.

RESULTS: The mean residual fluid score was 37 (Q1–Q3 35–39) for 3DD and 36 (Q1–Q3 34–38) for 1DD, residual stool — 48 (Q1–Q3 46–48) and 48 (Q1–Q3 47–48) respectively. The median residual fluid attenuation was 887 HU (Q1–Q3 725– 1238 HU) and 953 HU (Q1–Q3 668–1203 HU), the median of homogeneity — 77 HU (Q1–Q3 55–86 HU) and 59 HU (Q1– Q3 47–92 HU). There was no significant difference in these parameters between groups (p>0.05). Difficulty of dieting was statistically significantly higher in 3DD group compared to the 1DD group (p=0.012): 26 patients (47.3%) from the 3DD group and 13 patients (25%). Readiness to repeat the procedure was significantly higher in 1DD group 75,0% (39 patients) than in 3DD group 54,5% (30 patients) (p=0.027).

DISCUSSION: A one-day diet before CTC provides optimal quality of preparation, and changing the diet from a three-day to a one-day increases the tolerability of the preparation in general, and also increases the willingness of patients to repeat the procedure in the future. The study also showed that there was no benefit to a clear liquid diet in preparation for CTC. For both diet options (one-day and three-day), the quality of preparation was high, and there were no statistically significant differences in the quality of preparation between groups.

CONCLUSION: Changing the diet from three-day to one-day doesn’t affect the quality of preparation for CTC, but increases patient’s tolerability and readiness to repeat the procedure.