Certain patient populations are more challenging when it comes to bowel prep. To help colonoscopists address this, researchers in Italy recently reviewed literature about and summarized recommendations for bowel prep in various populations known to be more difficult to prepare adequately for colonoscopy.

Aside from noting prep solution- and procedure-related factors—the type of solution and its tolerability, the preparation regimen, pre-procedure diet, and the time between preparation completion and colonoscopy—the experts pointed out several patient clinical factors that influence the likelihood of successful bowel prep (World J Gastroenterol 2023;29[11]:1685-1707).

One such notable factor is the presence of chronic kidney disease (CKD), according to the authors, due to the potential of certain solutions to cause an electrolyte imbalance or worsen renal function. They recommend judicious use of laxatives and the avoidance of magnesium-based preps and sodium phosphate in patients with CKD. In addition, the authors noted that low-volume polyethylene glycol (PEG) solutions with ascorbic acid are preferred to high-volume PEG solutions to reduce excessive fluid intake. However, they cautioned that ascorbic acid may be associated with acidosis and renal stone formation. In the case of patients with creatinine clearance of less than 30 mL per minute, they recommend isotonic high-volume PEG solutions.

Older patients also can be difficult to prep adequately, the reviewers noted, citing a study that found older adults were nearly twice as likely to have inadequate cleansing than younger patients. To improve the chances of adequate cleansing, the authors recommended an extended low-fiber diet, a split preparation regimen and initiation of the colonoscopy within five hours of prep completion. In addition, they recommend a 1-L PEG prep over larger volumes of prep to improve compliance.

Patients with heart failure also were highlighted by the authors as a population that can be challenging to prep for colonoscopy due to the potential for the bowel prep solutions to exacerbate the patients’ cardiovascular issues. Specifically, the solutions can increase plasma volume and cause electrolyte imbalances. Since thiazide diuretics and selective serotonin reuptake inhibitors also can result in fluid and electrolyte imbalances, the reviewers recommend that these drugs be avoided in patients with heart failure during bowel prep.

In their review, the authors provided recommendations for improving bowel prep in numerous additional difficult-to-prep patient populations, including hospitalized patients; those with obesity, diabetes, chronic constipation, inflammatory bowel disease or liver cirrhosis; patients receiving multiple pharmaceutical agents; and those with a history of colorectal surgery or poor bowel prep.

—Natasha Albaneze, MPH