Safety of Polyethylene Glycol Solution plus Ascorbic Acid for Bowel Preparation for Colonoscopy in Patients with Chronic Kidney Disease

High volume, low volume, or pills, which way should we go? a review of bowel preparation for colonoscopy

PURPOSE OF REVIEW

Colorectal cancer (CRC) is the second leading cause of adult cancer-related deaths in the United States. Colonoscopy is the gold standard for CRC screening. Adequate bowel preparation prior to colonoscopy is essential for good visualization, which results in higher polyp detection rates and shorter procedural times. Achieving adequate preparation prior to colonoscopy is accomplished approximately 75% of the time. This review covers current recommendations and recent updates in bowel preparation for colonoscopy.

RECENT FINDINGS

Split-dose bowel preparation is recommended, but recent studies show that same day, low-volume preparations are noninferior. Low-volume polyethylene glycol with electrolytes + ascorbic acid can achieve high-quality bowel preparation and 1-day, low-residue diets prior to colonoscopy, particularly prepackaged low-residue diets, can lead to better outcomes. Utilizing visual aids and artificial intelligence in the form of smartphone applications and quality prediction systems can also lead to higher rates of bowel preparation adequacy.

SUMMARY

An individualized approach should be used to decide on the best preparation option for patients. Lower volume, same day preparations are available and lead to better patient tolerability and compliance, along with less stringent precolonoscopy diets. Smartphone applications and artificial intelligence will allow us to better educate and guide patients with regards to following preparation instructions.

Factors affecting the quality of bowel preparation for colonoscopy in hard-to-prepare patients: Evidence from the literature

Adequate bowel cleansing is critical for a high-quality colonoscopy because it affects diagnostic accuracy and adenoma detection. Nevertheless, almost a quarter of procedures are still carried out with suboptimal preparation, resulting in longer procedure times, higher risk of complications, and higher likelihood of missing lesions. Current guidelines recommend high-volume or low-volume polyethylene glycol (PEG)/non-PEG-based split-dose regimens. In patients who have had insufficient bowel cleansing, the colonoscopy should be repeated the same day or the next day with additional bowel cleansing as a salvage option. A strategy that includes a prolonged low-fiber diet, a split preparation regimen, and a colonoscopy within 5 h of the end of preparation may increase cleansing success rates in the elderly. Furthermore, even though no specific product is specifically recommended in the other cases for difficult-to-prepare patients, clinical evidence suggests that 1-L PEG plus ascorbic acid preparation are associated with higher cleansing success in hospitalized and inflammatory bowel disease patients. Patients with severe renal insufficiency (creatinine clearance < 30 mL/min) should be prepared with isotonic high volume PEG solutions. Few data on cirrhotic patients are currently available, and no trials have been conducted in this population. An accurate characterization of procedural and patient variables may lead to a more personalized approach to bowel preparation, especially in patients undergoing resection of left colon lesions, where intestinal preparation has a poor outcome. The purpose of this review was to summarize the evidence on the risk factors influencing the quality of bowel cleansing in difficult-to-prepare patients, as well as strategies to improve colonoscopy preparation in these patients.