Fast-acting laxatives are generally osmotic laxatives, such as Keserol, polyethylene glycol and lactulose. 1. Keserol: its main active ingredient is glycerol, mainly for pediatric and elderly constipation patients, the use of clean enema, that is, from the anus to give medicine. Its main mechanism is to lubricate and stimulate the intestinal wall to secrete mucus, lubricate the stool, and soften the stool to promote the discharge of stool. However, prolonged use of cecrops tends to dry out the intestinal tract and form habitual constipation. 2. Polyethylene glycol and lactulose: (1) Both of these drugs are taken orally, and their main effect is laxative and detoxification, which is mainly used for elderly patients. The mechanism of action is that after taking the drug orally, the drug enters the digestive tract to the intestines, and because of its high osmolality, it prompts the intestinal wall to secrete more mucus, lubricates the intestinal wall, softens the stool, and promotes intestinal peristalsis, which in turn promotes defecation. (2) Polyethylene glycol should not increase the dosage without authorization, otherwise it is easy to cause diarrhea; Polyethylene glycol is prohibited when patients have unexplained abdominal pain or intestinal diseases such as intestinal perforation, intestinal obstruction, gastrointestinal bleeding, and so on. (3) Individual patients may have nausea, vomiting and other intestinal adverse reactions when taking lactulose, lactulose is prohibited in patients with unexplained abdominal pain, and diabetic patients should be cautious, as it is easy to cause elevated blood sugar. The above drugs are recommended to be used under the guidance of a doctor, and the use of monitoring electrolyte changes, pay attention to maintaining the hydroelectric acid-base balance, not unauthorized use of drugs.