What are laxatives?

, medical expert
Last reviewed: 19.10.2021

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Laxatives are far from being limited to castor oil. They are of different types: lubricating, saline, stimulating, softening. They are also divided into groups: oral and rectal. How to understand all this variety of laxatives? What are the properties of each of them?

Lubricating laxatives

Mineral oil (liquid paraffin) very well softens the stool. Like plasticizers (softeners of stools), mineral oil is used for patients who need to avoid stress (for example, after surgery to remove a hernia, excising hemorrhoid cones, heart attacks and childbirth.

Precautions when using lubricating laxatives

Mineral oil should be avoided by people taking blood thinners, such as warfarin (Coumadin). Mineral oil reduces the absorption of vitamin K (an important vitamin for the formation of coagulation factors) from the intestine. Reducing the absorption of vitamin K in patients taking warfarin can potentially lead to "super-thinning" of blood cells and an increased risk of excessive bleeding.

Mineral oil should not be taken during pregnancy, as it may interfere with the absorption of vitamins and reduce the availability of vitamin K for the fetus.

Mineral oils can lead to pneumonia if it seizes the lungs. Some people (for example, very young, elderly, especially the victims of a stroke) are prone to aspiration, especially when lying down. Thus, mineral oils should not be given before bedtime or to those individuals who are prone to aspiration (the "suction" effect, which has the property of arising due to the creation of a reduced pressure).

Mineral oils for laxatives should be used only for short periods of time. Significant absorption of mineral oil in the body can occur if you use it repeatedly for a long time.

Stimulating laxatives

Stimulant laxatives cause bowel movements by increasing the contraction of the intestinal muscles, and they are effective when used on a short-term basis. Examples include stimulant laxatives - aloe, cascara, senna compounds, bisacodyl and castor oil. Bisacodyl (Dulcolax, Correctol) is available without a prescription in the oral form - tablets and in the form of suppositories or enemas. Assimilation of oral laxatives takes from 6 to 10 hours.

Bisacodyl is commonly used in colon cleansing for colonoscopy, barium enema and intestinal surgery. Effective for occasional constipation, bisacodyl should not be taken for more than a week, and the doctor must monitor its repeated use.

Other laxative stimulants include Senna (Ex-Lax, Senokot), Cascaru Sagrada (Remedy), and casanthranol

These laxatives are converted by colon bacteria into active compounds, which can then stimulate contractions in the muscles of the large intestine. After taking these products orally, bowel movements occur after 8 to 24 hours. Prolonged, chronic use of these laxatives can lead to darkening of the mucous membrane of the colon (melanoma bacillus) due to the accumulation of dark pigment (melanin).

Castor oil (concentrate)

It is an analog of a stimulant laxative, which works in the small intestine. It leads to the accumulation of fluid in the small intestine and facilitates the evacuation of stool from the intestine. Castor oil should not be taken with food, although juice or other flavored liquids can help hide its unpleasant taste. This laxative acts fairly quickly, usually for 2 to 6 hours.

Castor oil is usually used to cleanse the colon before surgery, irrigoscopy or colonoscopy. The absorption of nutrients and minerals in the small intestine can be disturbed by the frequent use of castor oil. This medication is not recommended for repeated treatment of constipation.

Precautionary measures

The intensity of the effect of stimulant laxatives is dangerous, so you need to monitor their doses. A large dose of any stimulant laxative can cause serious side effects.

Side effects include severe seizures, loss of excess fluid and dehydration, electrolyte disorders of the blood composition, such as too low a level of potassium blood (hypokalemia), as well as chronic malnutrition.

There is a fear that chronic, long-term use of stimulant laxatives can lead to loss of colon function (weakened colon). After several years or decades of frequent use of stimulant laxatives, the nerves of the colon slowly disappear, the muscles of the colon dry up and the colon becomes dilated.

Consequently, constipation can become increasingly difficult and a person reacts more strongly to laxatives. It is unclear, however, what will happen sooner: a progressive decrease in the function of the colon, which leads to the use of stimulant laxatives or the use of laxatives, which leads to a decrease in the function of the colon. However, prolonged use of stimulant laxatives is usually used after other treatments fail.

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Saline and osmotic laxatives

The active ingredients in salt laxatives are mainly magnesium sulfate, citrate and phosphate ions. These ions accumulate water in the intestine.

Additional water softens the stool, increases pressure in the intestines, increases intestinal contractions as a result of a soft stool release. Phosphoric soda, milk of magnesia and magnesium citrate are examples of salt laxatives.

Oral doses of saline laxatives should be taken with one or two glasses of water.

The bowel response, as a rule, begins in a period of time from 1/2 to 3 hours after taking a laxative. Small doses are sometimes recommended for the treatment of accidental constipation, while large doses can lead to a complete evacuation of the intestine. Complete cleansing of the intestine is useful in preparing for colonoscopy, sigmoidoscopy and irrigoscopy.

Active ingredients in laxative osmotic types, such as Golytely, GlycoLax and MiraLax are examples of polyethylene glycol (PEG). These ingredients work to wet the stool to soften it and increase the number of defecations. Laxative osmotic types are often used to cleanse the colon before colonoscopy or colon surgery.

Precautionary measures

Since in laxatives there may be some active ingredients that provide for the absorption of toxins from the intestine into the blood, saline laxatives should not be used for certain individuals. People with impaired renal function should not use laxatives containing magnesium, or phosphate salts. Excessive accumulation of magnesium and phosphate in the blood of these people can lead to excessive toxicity. Those who need to limit sodium intake, for example, people with congestive heart failure, kidney disease, high blood pressure, do not use laxatives that contain sodium.

Side effects of laxative osmotic type include nausea, abdominal cramps, or gas formation. People who have a history of abdominal or intestinal obstruction should consult their physician before using laxatives. Care is advised when using this medication for the elderly, as they may be more sensitive to its side effects, especially diarrhea.

Plasticizers of the stool (softening laxatives)

The plasticizers of the stool, called softening laxatives, help prevent stool hardening by adding moisture to the stool. The active ingredient in most stool softeners is a drug called docusate. Means containing docusate, by themselves, do not stimulate bowel movements or increase the amount of feces. They are used more to prevent constipation than to treat them.

Stool plasticizers are generally recommended for people who should avoid tension during defecation, including: for patients who depart from abdominal, pelvic or rectal surgery, childbirth or heart attack for people with severe high blood pressure or abdominal hernia, and also for people with painful hemorrhoids and / or anal fissures.

Stool softening in these affected people can help reduce pain during defecation.

The plasticizers of the chair are available without a prescription and include Kolas, Surfak, they can be bought at a pharmacy or at a specialized store - these are products containing docusate. Some drugs (for example, Peri-Colase) combine a stool softener with stimulant laxatives to activate defecation.

Precautions when using stool softeners Stool plasticizers are generally safe and well tolerated. They should not be combined with mineral oils, laxatives, because stool softeners can lead to increased absorption and toxicity of these products. Mineral oils are drip-sucked into the body and can cause inflammation of the lymph glands, liver and spleen. Therefore, it is undesirable to use laxatives without consulting and controlling a doctor.

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