According to the mechanism of action can generally be divided into seven categories, namely contact, swelling, lubricating, intestinal dynamics, proprietary Chinese medicine, probiotics and softeners.
1.Contact laxatives
Old called stimulant laxatives, this is a class of laxatives that we are most familiar with. Because of the quick effect, easy to take, many constipation patients first choice after the disease is this type of medicine. In many laxative Chinese medicine and weight loss, beauty, detoxification products can also be seen in these ingredients. Clinically, they are divided into two categories.
(1) anthraquinones: representative drugs include rhubarb, senna, cassia and aloe vera, American raspberry bark, European raspberry bark, etc.. After oral administration, these drugs are decomposed into anthraquinones by bacteria in the large intestine, and most of them reach the large intestine directly without being absorbed because of the protection of sugar group, and are decomposed into glycosides and sugars by bacterial enzymes in the intestine. The glycosides stimulate the mucous membrane of the large intestine and inhibit the absorption of sodium ions from the intestinal lumen, which increases water in the large intestine and causes diarrhea due to hyper-peristalsis. Defecation 6 to 8 hours after the drug, commonly used in acute and chronic constipation.
(2) diphenylmethane class: the representative drugs are phenolphthalein, bishacodyl (poo stop), sodium picosulfate, etc.. Phenolphthalein is a lot of constipation patients have eaten fruit guide tablets, after oral intake in the intestinal tract and alkaline intestinal fluid to form soluble sodium salts, can promote colon peristalsis. It is suitable for chronic constipation because of its mild effect and soft stool discharge in 6-8 hours after taking the drug. Bisacodyl can be used for chronic constipation or for endoscopy or preoperative bowel cleansing.
This type of medicine is mainly used for temporary laxation and should not be used continuously for more than half a month. If taken for a long time, some of the following adverse effects can occur.
(1) Serious drug dependence can occur, the dosage of drugs will become increasingly large, and even damage the peripheral nerves and muscle tissue of the intestinal wall, causing weakness of the large intestinal muscles, from functional lesions to the development of difficult to treat organic constipation.
(2) rhubarb, senna, cassia, etc. contain “anthracene” compounds, which will be deposited in the intestinal mucosa over time, turning the intestinal surface black and nigrosis, and this change may increase the risk of colon cancer.
(3) In addition, the intestinal ecological environment will be damaged, the balance of bifidobacteria and other beneficial bacteria will be imbalanced, the normal pH value in the intestinal cavity will be changed, a large amount of water secreted by the intestine will be lost, and symptoms of dehydration will occur.
2.Expansive laxatives
Also known as volumetric laxatives, or osmotic laxatives. These drugs are not absorbed by the stomach and small intestine, and can absorb water in the large intestine, soften the stool, increase the volume of stool, expand in the intestine to stimulate intestinal peristalsis, thus enabling laxation.
(1) Salts and alcohols are strong laxatives, which are effective 1-3 days after taking, and are mainly used for human detoxification and intestinal preparation before colonoscopy. Rarely used for the routine treatment of constipation, long use can cause electrolyte disorders, such as hypomagnesemia, hyperkalemia, hypernatremia and hypocalcemia. Magnesium sulfate, sodium sulfate can also cause reflex pelvic congestion and water loss, menstruation, pregnancy and elderly women use with caution.
(2) lactulose and dulcolax of disaccharides, these two drugs are not absorbed by hydrolysis in the small intestine, its permeability so that water and electrolytes are retained in the intestinal cavity, in the colon bacteria will break it down into lactic acid, acetic acid, so that the intestinal osmotic pressure further increases, so that the volume of feces increases, stimulating intestinal peristalsis, producing a gentle diarrheal effect, but also conducive to the excretion of ammonia and other nitrogenous substances. It takes effect 24-48 hours after oral administration. It is especially suitable for the elderly, pregnant women, children and those with post-operative constipation. The disadvantage is that it produces gas by fermentation under the action of bacteria, causing abdominal distension and other discomfort.
(3) Food cellulose includes natural and semi-synthetic polysaccharides and cellulose derivatives such as methyl cellulose and carboxymethyl cellulose in vegetables and fruits that are not absorbed by the intestine, increasing intestinal volume and keeping stool wet and soft, with good laxative effect. It can prevent and control functional constipation.
(4) Glycerin is the main component of the open plug. After injecting into the rectum through the anus, it stimulates the intestinal wall to cause defecation due to high osmotic pressure and has the effect of local lubrication, causing defecation within a few minutes. It is suitable for children and the elderly.
3.Lubricating laxative
Also known as stool softeners, oral intestine is not absorbed, and impede the absorption of water, so there is a softening of the stool lubricating effect of the intestinal wall.
Commonly used drugs are liquid paraffin, commonly used amount of 5 to 15 ml / time. As well as fire hemp seeds, almonds, etc.
It is suitable for hemorrhoids, hypertension, post-surgery, constipation in the elderly and children. Disadvantages are poor taste, weak effect, long-term application will prevent the absorption of fat-soluble vitamins AD, K, and calcium, phosphorus, so should not be used for a long time.
4.Intestinal power medicine
Can increase the rate of transmission of the whole gastrointestinal tract, increase the number of bowel movements, improve the sensitivity of the rectum to dilatation. But often need to be used in combination with other drugs.
Representative drugs are cisapride, mosapride, prilucapride succinate tablets (Lilo), etc..
The use of such drugs to exclude organic lesions of the intestinal tract.
5.Chinese patent medicine
The representative medicines include Ma Ren Wan, Liu Wei An Xie Capsules, Si Mo Tang, Ma Ren Zhi Spleen Wan, Fang Feng Tong Sheng Wan, Gardenia Gold Flower Wan, Niu Huang Shang Qing Wan, Shu Secret Capsules, etc..
When using should read the instructions carefully, control the amount of medication, time, to prevent adverse reactions.
6.Probiotics
Representative drugs are bifidobacterium, Pepcid, whole intestine raw, the United States intestinal security.
Can supplement the intestinal beneficial bacteria, softening stool, promote intestinal peristalsis role.
7, stool softeners
Can soften the stool, easy to discharge. For taking certain prescription drugs or sedentary constipation is more effective, but the effect is slow, generally 1 to 3 days to take effect.
Representative drugs include sodium docusate.
After understanding the various drugs for constipation, you should also be reminded that you should not rely solely on medication, but also start by changing your lifestyle, developing good habits, exercising moderately, and eating more foods rich in plant fiber. Psychotherapy, including biofeedback therapy, is often more effective for constipated patients suffering from irritable bowel syndrome. For some long-term constipation with a variety of drugs is still not effective, you can also consider surgery.