A Pilot Study of Endoluminal US for Stool Liquefaction

Document Type


Department or Administrative Unit


Publication Date



BACKGROUND: There is a need to cleanse patients who are poorly prepared for colonoscopy safely and efficiently during the procedure to minimize rescheduling. US is already being used in catheter-based intravascular thrombolysis, and time-reversal acoustic (TRA) has been explored in assisting drug delivery to the brain.

OBJECTIVE: To explore the efficacy and safety of a miniaturized endoluminal US device in stool dissolution as a means to salvage poor bowel preparation.

DESIGN: Proof of concept experimental study.

SETTINGS: Animal laboratory.

INTERVENTIONS: Low-frequency US and TRAs.

MAIN OUTCOME MEASUREMENTS: Feasibility, efficacy, and safety of US to liquefy stools ex vivo.

RESULTS: Depending on parameters, such as pulse rate, acoustic intensity, and duration, increases in liquefaction speeds by a factor of 50 and 100 times were obtained. There was a significant difference in weight change between the 20-kHz-treated sample compared with controls (P ≤ .0001). There was no difference in sloughing of mucosa and mechanical injury among the US, water spray, and control groups.

LIMITATIONS: Animal model.

CONCLUSION: Endoluminal US can liquefy stools at acoustic exposure levels that do not damage ex vivo colonic mucosa. Endoluminal US should be able to dissolve stools more rapidly than water spray alone, thereby optimizing colonoscopic evaluation in vivo.


This article was originally published in Gastrointestinal Endoscopy. The full-text article from the publisher can be found here.

Due to copyright restrictions, this article is not available for free download through ScholarWorks @ CWU.


Gastrointestinal Endoscopy


Copyright © 2014 by the American Society for Gastrointestinal Endoscopy