Unsedated Colonoscopy and the Water Method for Minimizing Discomfort in the Unsedated Patients

ABSTRACT

A decade ago, failure of cecal intubation due to pain in ~20% of scheduled unsedated patients in the author's veterans practice prompted the search for a less uncomfortable approach. Methods that minimized discomfort or enhance cecal intubation included use of pediatric, variable stiffness, computer-assisted, 3-dimensional magnetic imaging colonoscope, gastroscope, and inhalation of nitrous oxide or insufflation of carbon dioxide; use of hypnosis, music, audio distraction, or simply allowing patients to participate in medication administration. In addition, several water-related techniques (as adjuncts to air insufflation) enhanced speed and success of intubation, reduced discomfort but did not appear to alter the amount of medications used. Because of simplicity, the water-related techniques added to turning off of the air pump were evaluated in a series of trial-and-error modifications. The result was the development of a water infusion in lieu of air insufflation method. Subsequent refinements included suction removal of all residual air to minimize angulations at flexures. Water exchange during insertion was used to suspend and removal feces to clear the luminal view while distention of the colonic lumen was minimize. Observational studies followed by randomized controlled trials confirmed the water method (simplified nomenclature) had significant impacts on discomfort both during and after colonoscopy: reduction of medication requirement; attenuation of insertion-related discomfort, enhancement of cecal intubation, decrease of pain after colonoscopy, increase in reported willingness to repeat unsedated colonoscopy in the patients examined without sedation and reduction of recovery time burden in patients accepting the option of sedation on demand.