Published online Nov 5, 2021. doi: 10.4292/wjgpt.v12.i6.103
Peer-review started: March 1, 2021
First decision: April 18, 2021
Revised: May 2, 2021
Accepted: September 3, 2021
Article in press: September 3, 2021
Published online: November 5, 2021
Processing time: 245 Days and 20.2 Hours
Colon capsule endoscopy (CCE) has emerged as a valuable tool in gastroenterology. There remains significant variation in bowel preparation and booster preparations between capsule endoscopy centres. Currently, there is limited data available on the use of castor oil as an additional agent in booster regimens for CCE. Our study is the largest study to date that assesses the use of castor oil in CCE procedures prospectively in a western population.
Our capsule endoscopy centre recognises the suboptimal completion rates of CCE, in our centre and worldwide, and investigates the addition of castor oil in improving this. With this study, we aim to add to the limited available data on castor oil in CCE preparation regimens and highlight the need for further research.
Our main objective was to assess the impact of adding castor oil to a standard split-dose (2-d) preparation in an unselected Western patient cohort in our CCE practice. Our secondary objectives included studying the impact of castor oil on diagnostic yield and identifying patient factors associated with CCE completion and/or more likely to benefit from castor oil. Our study suggests that adding castor oil is significantly associated with higher capsule completion rates and in turn, higher diagnostic yield. This highlights the need for further research in this field, as completion rates is a recognised limitation of this diagnostic test.
Our study identified a retrospective “control” arm (without castor oil) and collected data on a prospective “cases” arm (with castor oil), employing a 2:1 nested control: case design, in assessing the benefit of adding castor oil to a 2-d bowel preparation regimen in our CCE practice. We utilised student t and chi-square tests when comparing basic demographics, completion rates, image quality, colonic transit time, diagnostic yield and polyp detection between the two groups. This was a novel study methodology, with respect to castor oil use, yet to be replicated in other centres.
Our study evaluated 186 CCE procedures (62 cases and 124 controls). We found that overall CCE completion was 77% and was significantly higher in the castor oil group with 87% vs 73%. This effect of castor oil appears to be more effective in older populations and females. Interestingly, positivity rates and polyp detection rates also increased with the addition of castor oil, 84% vs 46% and 82% vs 44%, respectively. Reassuringly, adding castor oil did not reduce image quality or colonic transit time.
What are the new theories that this study proposes? – Castor oil not only improves completion rates but also has potential to improve diagnostic yield of CCE. Castor oil appears safe and acceptable by patients and can be used in an unselected cohort with little to no adverse events. What are the new methods that this study proposed? – This study proposes the addition of low dose castor oil as a booster agent to a standard split-dose CCE bowel preparation.
What is the direction of the future research? - There is a need to explore and expand on research of using castor oil in CCE in different populations, alternative doses and in combination with other bowel preparation regimens, with the aim of improving CCE performance parameters.