Before colonoscopy examination, you can take polyethylene glycol electrolyte bulk, compound sodium hydrogen phosphate tablets, magnesium sulfate and other types of drugs, polyethylene glycol electrolyte bulk main ingredients are polyethylene glycol, anhydrous sodium sulfate, sodium chloride, etc. In medical clinic, this drug is mainly used for intestinal endoscopy or preoperative preparations, because this drug contains formulated electrolytes, so it can effectively prevent the electrolyte exchange of the body’s intestinal fluids. Compound sodium hydrogen phosphate tablets as a salt laxative, which can reduce the intestinal water absorption through the role of high osmotic pressure, accelerate the discharge of substances in the body, which is suitable for rectal, colorectal, sigmoid colonoscopy, or barium meal contrast examination of the intestinal contents of the cleanup of the treatment before the examination. Magnesium sulfate as a diarrhea agent application, need to cooperate with calcium gluconate, sodium chloride and other types of drugs for joint use, so as not to cause patients to have electrolyte disorders, dehydration and other secondary conditions.