Castor oil as booster for colon capsule endoscopy preparation reduction: A prospective pilot study and patient questionnaire

An evaluation of a novel bowel preparation regimen and its effect on the utility of colon capsule endoscopy: a prospective cohort study with historical controls

BACKGROUND

The aim of this study was to evaluate the efficacy of a novel bowel preparation and booster regimen for colon capsule endoscopy (CCE) using macrogol, phospho-soda and gastrografin, compared with a control regimen consisting of polyethylene glycol and sodium picosulfate.

METHODS

This was a prospective cohort study using historical controls. Symptomatic patients undergoing CCE between 11/07/2021 and 21/12/2021 using the novel regimen were included. Symptomatic patients who underwent CCE in the ScotCap evaluation using the control regimen were used as historical controls. We measured the rate of complete test (visualisation of the whole colon and rectum), adequate bowel preparation, successful test (complete and adequate bowel preparation) and need for further test following CCE. The rate of adverse events was also collected.

RESULTS

Patients undergoing CCE using the new and control regimen were 200 and 316, respectively. The median age, age range and proportion of female patients in the new and control regimen cohorts was 61 vs 60 years, 16-86 vs 20-83 years, and 60.5% vs 56.6%. The rate of complete test, adequate bowel reparation and successful test for the new and control regimen was 69% vs 72.2%, 86.6% vs 80.7% and 60.5% vs 65.8%. Comparing the new and control regimen, 39.5% vs 37.3% of patients required no test following CCE, 26% vs 32.6% required a colonoscopy, 31.5% vs 21.5% required a flexible sigmoidoscopy and 3% vs 2.9% required a computed tomography colonogram. No adverse events were reported using the new regimen compared to 2 (0.6%) in the control group.

CONCLUSIONS

The rate of adequate bowel preparation has improved following the introduction of a new regimen. However, further work is needed to increase the complete test rate. A significant proportion of patients continue to avoid colonoscopy following CCE.

Efficacy of the Castor Oil-Filled Capsule Method as Preparation for Colon Capsule Endoscopy

BACKGROUND

Colon capsule endoscopy (CCE) is useful as an alternative examination for patients in whom colonoscopy is difficult. The Japanese Association for Capsule Endoscopy has published a recommended regimen for CCE using castor oil, which is becoming a standard examination method for CCE in Japan. However, castor oil has an unpleasant flavor. Therefore, patient acceptance is not good.

OBJECTIVES

The aims were to develop a castor oil-filled capsule and evaluate its feasibility and patient acceptance in a retrospective, comparative study.

METHOD

A dissolution study of pig-derived gelatin capsules filled with castor oil was performed using artificial gastric juice. The CCE excretion rates within battery lifetime, CCE examination times, endoscopic colonic cleansing levels, and patient acceptability between CCE boosters with a castor oil-filled capsule and without castor oil were retrospectively compared using medical information, clinical data, and endoscopic findings at Takada Chuo Hospital from September 2016 to August 2019.

RESULTS

The castor oil-filled capsules were completely disintegrated at approximately 1-3 min in artificial gastric juice. Bowel preparation with oil-filled capsules and without castor oil was performed in 27 and 24 patients, respectively. CCE excretion rates within battery life were 100% and 91.7% (p = 0.217), small bowel transit times were 115 min and 143 min (p = 0.046), colon transit times were 168 min and 148 min (p = 0.733), and adequate colonic cleansing rates were 85.2% and 86.3% (p = 1.000) in patients using bowel preparation with and without oil-filled capsules, respectively. Regarding acceptance, the taste was not problematic in 85.2%, and tolerability for the next CCE was 96.3%.

CONCLUSIONS

CCE using a castor oil-filled capsule method achieved high examination performance and sufficient patient tolerability.

Castor Oil in Bowel Preparation Regimens for Colon Capsule Endoscopy: A Systematic Review with Meta-Analysis

Completing colon capsule endoscopy (CCE) investigations rely on successful transit and acceptable bowel preparation quality. We investigated the effect of adding castor oil to the CCE bowel preparation regimen on the completion rate using a meta-analysis of existing literature. We conducted a systematic literature search in PubMed, Web of Science, and Embase. Included studies underwent quality assessment, and data for meta-analysis were extracted. Pooled estimates for excretion rate and acceptable bowel preparation rate were calculated. We identified 72 studies matching our search criteria, and six were included in the meta-analysis. Three of the studies had control groups, although two used historical cohorts. The pooled excretion rate (92%) was significantly higher in patients who received castor oil than in those who did not (73%). No significant difference in acceptable colonic cleanliness was observed. Castor oil has been used in a few studies as a booster for CCE. This meta-analysis shows the potential for this medication to improve excretion rates, and castor oil could be actively considered in conjunction with other emerging laxative regimens in CCE. Still, prospective randomized trials with appropriate control groups should be conducted before any conclusions can be drawn. Prospero ID: CRD42022338939.