This invention relates, e.g., to a composition comprising two or more of: (a) N-acetylcysteine and/or (b) simethicone and/or (c) a docusate salt. In one embodiment of the invention, the amounts of (a) and/or (b) and/or (c) are effective, when the composition is administered into a colon of a subject undergoing colonoscopy, to cleanse a region of the colon in the visual field of the colonoscope so that the region contains no adherent stool or intestinal secretions obscuring the visual field. Methods for using this or other compositions of the invention, e.g. to cleanse the colon of a subject in order to enhance visualization of the colon during a colonoscopy, are also described, as are kits for carrying out methods of the invention.