What is a common agent used for bowel cleansing before a colonoscopy?

Polyethylene glycol (PEG) solution is commonly used for bowel cleansing before a colonoscopy due to its effectiveness in thoroughly evacuating the intestinal contents. This agent works by osmotically drawing water into the bowel, which helps to soften the stool and increase the volume of intestinal contents, facilitating a clear and effective cleanse. Using PEG solutions often results in fewer side effects, such as cramping or bloating, compared to other cleansing agents.

PEG solutions are typically designed to be well-tolerated, requiring the patient to consume large volumes of the solution over a relatively short time period, which encourages a complete evacuation of the bowel. This is crucial for creating the best possible conditions during a colonoscopy, as a clean bowel allows for optimal visualization of the intestinal walls and any potential lesions or abnormalities.

Other agents, while they may have some utility for bowel preparation, do not match the efficiency or reliability of PEG solutions. For instance, bisacodyl is a stimulant laxative that can expedite bowel movement but may not ensure a clean and clear bowel. Lactulose, which is a sugar used mainly for treating constipation and liver disease, does not provide the same level of cleansing required before an endoscopic procedure. Magnesium hydroxide, similar to bisacodyl