Multicenter Retrospective Analysis Of Bowel Preparation Including Castor-Oil For Colon Capsule Endoscopy

Colon capsule endoscopy (CCE) has been expected to be a new modality for colorectal cancer screening. However, capsule excretion rates ranges from 70-90% in Japan. Hotta reported bowel preparation with castor oil was effective for improving the capsule excretion rate and reducing liquid loading (Open Journal of Medical Imaging, 2016, 6, 103-107).The aim of this study is to confirm its effectiveness at 4 medical centers in Japan. At 4 medical centers including Nagoya University Hospital, Fujita Health University Hospital, Masuko Memorial Hospital, and Kyoto Kujo Hospital, 409 examinees undergoing CCE were enrolled to evaluate the capsule excretion rate, transit time, intake volume of bowel preparation, and colorectal cleanliness. Before and after the introduction of castor oil, other preparation methods were basically unchanged. Of 409 examinees, 60 were excluded because capsules lodged proximal to small-bowel strictures, examinations were discontinued according to examinees’ hope, etc. The remaining 181 examinees (98 men and 83 women; median year of age, 59 (range 17-87) took a regimen without castor oil between November 2013 and June 2016, and the 168 examinees (109 men and 59 women; median year of age, 59 (range 17-88) took a regimen with castor oil between October 2015 and September 2017. Capsule excretion rates within its battery life in the groups without and with castor oil were 82% (148/181) and 96% (161/168), respectively ( P <0.0001). Capsule excretion rates within its battery life of men and women in the group without castor oil were 91% (89/98) and 71% (59/83, P =0.0012), while those in the group with castor oil were 95% (104/109) and 97% (57/59, P >0.999). Only in cases that adaptive frame rate function was turned on at capsule ingestion, small bowel transit time between the pylorus and the ileocecal valve in the groups without and with castor oil was 85 ± 39 min (n=66) and 76 ± 53 min (n=122), respectively ( P =0.0086). Colorectal transit time was 133 ± 127 min and 112 ± 89 min, respectively ( P =0.4750). The median (range) examination time from intake to excretion of CCE in the groups only with successful observation throughout the colorectum without and with castor oil was 255 ± 142 min and 233 ± 122 min, respectively ( P =0.1916). Median (range) volume of castor oil was 40 (15-180) mL used for booster after CCE entered the small bowel. Median (range) volume of total fluid and other lavage intake in the groups without and with castor oil was 3,514 ± 1,443 mL and 3,156 ± 1,160mL ( P =0.0144). Bowel preparation with castor oil for CCE was effective for improving the capsule excretion rate and reducing liquid loading.