There are a variety of medications that are commonly used to promote healthy bowel elimination. Which best describes a bulk-forming agent?

Choice A reason: Pulling fluid into the bowel describes osmotic laxatives (e.g., lactulose), which increase water content to soften stool and stimulate peristalsis. Bulk-forming agents work by absorbing water to increase stool volume, not by osmotically drawing fluid. Choice B reason: Bulk-forming agents (e.g., psyllium) absorb water in the intestine, swelling to form a bulky, soft stool that stimulates peristalsis. Taken with adequate water, they promote regular bowel movements, making this the accurate description. Choice C reason: Softening the fecal mass describes stool softeners (e.g., docusate), which reduce stool surface tension to allow water penetration. Bulk-forming agents primarily increase stool volume, not just soften it, distinguishing their mechanism. Choice D reason: Causing local irritation describes stimulant laxatives (e.g., bisacodyl), which irritate the mucosa to enhance motility and reduce water absorption. Bulk-forming agents work mechanically by adding bulk, not through chemical irritation.