The following drugs are available for bowel cleansing: 1, compound polyethylene glycol electrolyte dispersion: has the effect of maintaining water-electrolyte balance, so it is a drug that is currently being promoted in China. 2, magnesium sulfate: has the effect of diarrhea, also has the effect of bowel cleansing, but is prone to electrolyte disorders. 3, mannitol: has a certain effect on bowel cleansing, but is prone to gas production, so for patients with intestinal obstruction is relatively contraindicated. 4, fruit guide tablets, senna: these drugs are mainly to prevent constipation caused by intestinal obstruction, need to be taken orally before bowel cleansing. 5, other types of drugs: such as lactulose oral solution, bifidobacteria capsules and rhubarb liquid, these drugs can also play the effect of bowel cleansing, but the effect is relatively poor.