Colorectal cancer is the second most common cause of death in the United States. 1 A colonoscopy is the current gold standard for prevention and early detection of colorectal cancers. During a colonoscopy procedure, polyps and lesions are biopsied and removed. The most effective method of colon cleansing for the procedure is achieved by using one of several commercially available colon lavage preparations. Before the colonoscopy, patients are prescribed and instructed to take one of these bowel preparations.
Background
Adequate bowel preparation is defined as sufficient for identification of polyps > 5 mm.2 The impact of inadequate bowel preparation extends beyond the need for additional or repeat procedure(s) and includes potentially missed polyps and cancers. Inferior bowel preparation quality is associated with a significant decrease in the detection of flat or sessile serrated polyps.3 Missed polyps increase the risk of interval colorectal cancers. A high-quality bowel preparation together with the individual skill and experience of the endoscopist are crucial for adequate polyp detection. In addition, other risks of inadequate bowel preparation and repeated colonoscopies reduce adenoma detection rates, undetected carcinomas, and increase the risk of complications, possibly resulting in lawsuits.3
A major difficulty facing the Veterans Health Administration (VHA) medical center gastroenterologists is what to do when a patient is not properly prepared after standard prescreening education and the bowel preparation regimen. Traditionally, the patient is given additional medication and asked to return the next day for a repeat colonoscopy. Alternatively, the patient is given a 2-day bowel preparation to be used prior to a new appointment.
The choice of bowel preparation has been standardized within the US Department of Veterans Affairs (VA) Connecticut Healthcare System in West Haven (VACHS); therefore, it is out of the scope of this article to discuss regimens that we do not use. However, several other bowel preparation regimens are available and effective when all the directions are properly followed. The VACHS follows a standard 1-day colonoscopy preparation that excludes solid foods the entire day before the colonoscopy and drinking a split-dosing of 1-gallon colon electrolyte lavage (ie, one-half gallon on both the evening before and the morning of colonoscopy). The endoscopists use the 10-point Boston Bowel Preparation Scale to maintain a standardized manner of rating the quality of the bowel cleanout. One of 10 registered nurses (RNs) provides a colonoscopy preparation education class with a standardized slideshow and matching 1-day preparation instruction.
For patients who fail the standard 1-day preparation, the same trained RNs inquire about any difficulties in consuming the preparation and provide the standard 2-day bowel preparation instructions. Multiple factors impact the adherence with preparation directions. Several patient-specific factors, comorbidities, and medications can contribute to inadequate bowel preparation.4 These factors include failing to fast before the procedure; namely, consuming solid foods, not consuming the entire preparation, not taking the preparation as directed, and not consuming adequate amounts of clear liquids or calories. Other reasons for failing the preparation are nausea and vomiting, poor understanding of instructions (including illiteracy), chronic constipation, use of narcotics and psychotropic drugs, and lack of awareness of the consequences of inadequate bowel preparation.
A study by Hautefeuille and colleagues noted that approximately 20% of patients having colonoscopy failure were not adherent to bowel preparation instructions.5 Only 55% of patients were aware of these consequences; whereas 96% of physicians were convinced they had given appropriate and sufficient information.5 As noted earlier, approximately half of patients do not fully comprehend the need to follow all the instructions. Therefore, clear and concise cleansing instructions and patient adherence are key factors that contribute to efficiency and quality of colonoscopy. The preparation failure rate creates a large volume of repeat patients and contributes to reduced efficiency of outpatient endoscopic practice.