Opioids are typically prescribed in conjunction with either methylnaltrexone bromide or one of these drugs to prevent development of a condition called OIC. Usage of a class of these drugs derived from anthraquinone may cause a black staining of the lamina propria called melanosis coli. The indicator phenolphthalein was historically used as one of these drugs, but has been phased out due to carcinogenicity. An isomer of lactose named (*) lactulose functions as one of these drugs by acting as a hyperosmotic agent. Patients are given a large amount of fluids and one of these drugs, typically magnesium citrate or sodium picosulfate, in preparation for a colonoscopy. (10[1])For 10 points, name these drugs that increase bowel movements or soften stool, and are therefore used to treat constipation. ■END■