It is not usually necessary to take Dacronin Hydrochloride Gum Syrup for a colonoscopy, so there is no time to take it. Dacronin Hydrochloride Syrup is a local anesthetic, usually used when doing gastroscopy, can anesthetize the throat, also can play a certain lubrication, but also can remove the foam in the lumen, making the vision clearer, its penetration is also stronger, usually in 2-10 minutes can take effect, usually can maintain 2-4 hours. Before doing a colonoscopy you need to do a bowel preparation, rather than taking dacronine hydrochloride gelatin paste, bowel preparation can usually be applied mannitol, polyethylene glycol electrolyte dispersions, etc. or an enema to clean the bowel. This is so that the inside of the bowel can be seen clearly during the colonoscopy. Bowel preparation before colonoscopy must be carried out under the supervision of a doctor, and the above medications should not be taken by oneself.