Chronic constipation is more common. The prevalence of the elderly over 60 years old can reach 18.2%. If you can not timely treatment, effective relief of symptoms, often affect the quality of life and work efficiency, in the elderly or severe constipation patients often can also cause the occurrence of hernia, in addition, can also cause myocardial infarction or cerebrovascular accident, so constipation is not a small matter. Chronic constipation has a great deal to learn when choosing laxatives. The choice of drugs for the treatment of constipation, only to consider its efficacy and onset of action time not only does not meet the requirements of medical treatment, but also may produce dependence, so in the use of medication should also be considered in the treatment of drugs can be used for a long period of time, how safe, and whether the patient can be expected to have a good tolerance for the drug. At present, the commonly used domestic laxatives are: 1, volumetric laxatives (cellulose) can accelerate the colon or the whole gastrointestinal transit, adsorption of water, so that the stool is loose and easy to discharge, to relieve constipation and the sense of urgency of defecation; pectin, psyllium, oat bran and other soluble cellulose helps to maintain fecal water; and plant cellulose, lignin and other insoluble cellulose can increase the amount of stool. The advantages of cellulose preparations are that they are economical, safe, and suitable for all levels of health care; however, gastrointestinal distention occurs when more cellulose preparations are ingested, and should be filled in for patients with weak colon. Supplementation of cellulose is not immediately effective, the application of 7 to 10 days after the appropriate increase or decrease in dosage according to the specific circumstances. 2, salt laxatives (magnesium sulfate) oral magnesium sulfate in the intestinal tract is not easily absorbed, stay in the intestinal lumen to form a hypertonic state, diarrhea effect is strong and rapid, generally oral 2-6 hours after the discharge of watery or semi-fluid feces. It can cause serious adverse reactions and should be used with caution in clinical practice. At present, it is usually used for total colonoscopy or barium enema and other examinations before the bowel preparation. 3, stimulating laxatives (tomato laxative, rhamnosus, phenolphthalein, castor oil, etc.) Long-term use of stimulating laxatives can damage the patient’s enteric nervous system, and it is likely to be irreversible, that is, the production of drug dependence. (1) Phenolphthalein (fruit guide tablets): after oral intake in the intestine to form soluble sodium salt, stimulate the mucosa of the colon, promote peristalsis; and prevent the intestinal fluid is absorbed by the intestinal wall and diarrhea-inducing effect. Generally in 4~8 hours after the drug can be discharged semi-fluid soft stool, diarrhea and intestinal lumen fluid acidity and alkalinity. Appendicitis, intestinal bleeding, cardiac and renal insufficiency, hypertension, intestinal obstruction, infants and young children, pregnant women are prohibited. Clinical application 1~4 tablets each time, before going to bed. For those who make intestinal preparation before total colonoscopy, X-ray examination or operation, it should be taken 8 hours in advance. (2) Bisacodyl: after oral intestinal bacterial decomposition of the product and the drug itself on the intestinal wall have a strong stimulating effect, can increase intestinal peristalsis, promote defecation; at the same time, it can inhibit the Na +, Ca2 + and water absorption in the colon, so that the intestinal luminal content of the volume increased, causing reflex defecation. Clinically, it has high efficiency for acute and chronic constipation. It can also be used for intestinal emptying before delivery, surgery, abdominal X-ray examination or endoscopy, and restoring normal bowel habits after surgery and childbirth. It can cause abdominal pain and occasionally severe abdominal cramps after taking it. Acute abdomen, spasmodic constipation, severe hard stool, anal rupture or hemorrhoidal ulcer patients are prohibited, pregnant women should be used with caution. 4, osmotic laxatives [Fosamax (polyethylene glycol 4000), lactulose, etc.] (1) Lactulose: synthetic disaccharide, in the stomach and the small intestine is not decomposed and absorbed, after reaching the colon, through osmosis, so that the water and electrolytes are retained in the intestinal lumen; and by the intestinal tract normal bacterial flora decomposition for lactic acid and acetic acid, further increase the osmotic pressure in the intestinal lumen, resulting in diarrhea; to block the ammonia absorption; the acid metabolic products can stimulate the mucosa of the intestinal wall. Its acidic metabolism can stimulate the mucous membrane of intestinal wall, increase intestinal peristalsis and promote defecation. As lactulose decomposition in the body produces gas, so some patients will have abdominal distension, increased exhaust and other gastrointestinal flatulence. Excessive dosage can cause nausea, abdominal distension, diarrhea and hypokalemia, hypernatremia and so on. Contraindicated in gastrointestinal obstruction, diabetes mellitus or low sugar diet. The therapeutic dosage for patients with chronic constipation is 5-10g 1~2 times per day, and the dosage is suitable for keeping 2~3 soft stools per day. Clinical use for chronic functional constipation, including the elderly, children, infants and pregnant women of all age groups of patients with high safety. For patients with hepatic encephalopathy, after applying lactulose, it not only has the effect of keeping the stool smooth, but also reduces the absorption of ammonia, which is favorable to the recovery of hepatic encephalopathy. (2) Fosamax (polyethylene glycol 4000): it is a new drug for the treatment of chronic constipation which has been newly listed at home and abroad in recent years. The mechanism of action of Fosamax is physical, does not affect the colon transit time, it is neither degraded in the intestinal tract, nor produces organic acids or gases, does not change the acidity or alkalinity of the feces, does not affect the pH value of the intestinal tract, and does not change the normal bacterial flora of the intestinal tract, which is a kind of effective drug with very good safety. Chronic functional constipation patients can take Fosamax to take effect after 24~48 hours, and can maintain 1 stool per day 1 week after treatment. Fosamax does not contain salt, does not increase the cardiovascular burden, for hypertension, heart disease, renal insufficiency combined with constipation patients; at the same time, because it does not contain sugar, can also be used for diabetic patients; in elderly patients, Fosamax will not cause intestinal flatulence, will not have adverse effects on the heart, liver, renal function, and will not change the intestinal absorption function. For special patients, such as hemorrhoids after surgery, anal fissure, perianal abscess, long-term bedridden patients and postpartum bowel regularity of the restoration of the same application. Recently, there are also reports of polyethylene glycol used in children’s constipation. 5, pro-dynamic drugs (cisapride) is widely used in clinical gastrointestinal pro-dynamic drugs, belonging to the benzodiazepine class of drugs, its pro-dynamic effect directly on the upper section of the colon. It has been used in the treatment of constipation, but the efficacy is not certain. 6, lubricating laxative (Keselu liquid paraffin) (1) Keselu (containing magnesium sulfate, glycerol, propylene glycol): can lubricate and stimulate the intestinal wall, soften the stool, so that it is easy to discharge, adults 20ml / times. It is mainly suitable for patients with hard stool, especially the elderly patients. (2) Liquid paraffin: It is not absorbed or digested in the intestinal tract, lubricates the intestinal wall and makes the feces easy to be discharged. For old and weak, long-term bedridden patients with constipation, it should be noted that it has the possibility of causing lipid aspiration pneumonia, and long-term use can lead to fat-soluble vitamin deficiency. Adults 15~30ml / times, 6~8 hours after the drug to produce the effect, usually taken at bedtime. 7.Microecological preparation (Pepcid) Containing bifidobacteria, lactobacillus, enterococci and other normal intestinal flora. It is a good intestinal microecological regulator, directly supplementing the normal physiological flora and improving the intestinal microecological environment. However, it should be avoided in combination with antibiotics. The preparations for regulating intestinal microecology also include Mia BM and Rejuveno. Can be used as an adjunctive treatment for constipation. 8, Chinese medicine laxative In terms of Chinese medicine, constipation is divided into real constipation, false constipation. Heat constipation to clear heat and moisturize the bowel mainly, can take Ma Ren Pills; gas secretion should be gas conduction stagnation, to Suzi descending qi soup flavored. Deficiency constipation is also divided into qi deficiency, to benefit qi and moisten the bowel, with tonifying zhong yi qi soup plus subtractions; blood deficiency is desirable to nourish blood and moisten dryness, the four things soup can be used; cold condensation should be warmed through the opening of the secret, to warm the spleen soup plus flavor. If the Chinese herbal preparation contains drugs such as rhubarb, aloe vera and other stimulating laxative ingredients, it will likewise produce dependence on the drug, damage the patient’s enteric nervous system, and is likely to be irreversible. Therefore, prolonged application is not advocated. In short, in the treatment of chronic constipation, the use of inappropriate laxatives or laxatives applied in unreasonable doses may cause dehydration, electrolyte balance disorders and other adverse reactions. For patients with hypertension, heart disease, diabetes mellitus, renal insufficiency combined with constipation, safe laxatives should be used, such as polyethylene glycol 4000 (Fosamax).