Laxative and Purgative herbs (Virechana Karma)
Laxatives are herbs that in some way stimulate the bowels to promote bowel movements. This action is called by a number of different names depending on the strength, and usually their strength is considered to be dose dependent, with the more stimulating laxatives containing higher levels of anthraquinones. In order of effect they are:
Aperients (often Bitters, hepatics, and cholagogues)
Laxatives (Bulking or Osmotic & Stimulant)
Cathartics/Purgatives (quite violent remedies and not often used)
Laxative herbs promote bowel movement, dispel constipation, and help eliminate food accumulation and toxic build-ups from the intestines. Weak laxatives are called simply laxatives or aperients, strong laxatives are called purgatives or cathartics.
Purgatives promote forceful evacuation, and may cause diarrhea and griping, with perhaps pain and tenesmus, owing to what is often an irritant effect. As such, they should be used with much care. Purgatives are either cold, bitter herbs like rhubarb or hot oils like castor oil.
Mild laxatives are mainly moistening herbs and bulk laxatives, like flax. they lubricate the intestines and increase bowel movement.
Laxatives and purgatives are indicated whenever there is constipation, or when there is a pronounced coating at the back of the tongue, denoting a buildup of toxins in the colon. Sometimes a person who has regular bowel movements may still have a large accumulation of fecal matter in the colon and so require purgation. Whenever there are toxins in the colon, which may also cause diarrhea, purgatives can be used.
Chronic constipation, as well as constipation of the elderly, is usually a Vata condition of accumulation of gas and dryness of the colon. For this condition, generally mild, moistening or bulk laxatives are appropriate. However, sometimes a strong purge is necessary for a high buildup of toxins due to long standing constipation and accumulated Vata. In such cases, castor oil may be appropriate.
Pitta constitution tends towards diarrhea due to its heat and slightly oily attributes, but where heat is strong and long standing it may cause constipation. Either way, purgatives of a usually cold and bitter nature, which influence the small intestine, are appropriate. Purgation (virechana) is the strongest way to eliminate Pitta, heat and bile from the body.
When there is inflammation or ulceration of the intestinal membranes, which is usually a Pitta condition, strong purgatives can cause irritation. For such conditions moistening laxatives of a cooling nature, like psyllium seeds, would be appropriate.
Kapha constitution may be constipated owing to the accumulation of phlegm, mucus and undigested food particles in the intestines due to deficient digestive power (mandaagni) for this condition, laxatives of a drying nature are indicated. Bulk or moistening laxatives would increase congestion.
Laxatives tend to suppress the power of digestion, and may weaken peristalsis in the long run by over stimulation. As such they should be used with stimulant and/or carminative herbs, such as ginger and fennel seeds.
Constipation or toxins in the colon can also be treated by increasing the power of digestion (Agni). Hot spicy stimulant carminative herbs can help correct constipation in a vata or Kapha constitution without actually the use of laxatives.
Dryness in the colon may also be related to dryness in the lungs, and herbs that moisturize the lungs, like licorice or flax seed, may be more specific for the condition.
Typical moistening or bulk laxatives: bran, flax seed, ghee, licorice, prunes, raisins, psyllium seed, shatavari, warm milk.
Strong purgatives: aloe vera, castor oil, Epsom salt, rhubarb, senna.
Cooling herbs with various degree of laxative action: aloe vera, Echinacea, gentian, rhubarb, senna.
How Laxatives Work
There are 2 general modes of action for these herbs that are best categorized as either stimulating or osmotic laxatives.
Stimulating Laxatives are often those herbs that contain the plant constituent anthraquinones, and their action is to stimulate greater contractions of the muscle walls of the large intestine. This occurs between 8-12 hours after taking the remedy. A problem with this is that it might cause uncomfortable and gripping pain in the abdomen, and this can be alleviated with the use of a carminative. Note: Stimulating laxatives should not be used long term, and these herbs have a considerable number of safety concerns & contraindications. Herbal examples include:
Cassia angustifolia (Senna)
Rheum palmatum (Turkey Rhubarb)
Rhamnuspurshiana (Cascara)
Arctiumlappa (Burdock)
Rumexcrispus (Yellow dock)
Hepatics, cholagogues and choleretics can also improve bowel function by activating the liver & gallbladder, creating a reflex activation of the bowel that tends to improve the tone of the colon musculature.
Osmotic or bulking Laxatives draw water to themselves and hold it in the colon, serving to soften the stool and give it bulk (also called bulking agents or stool softeners).
Linumusitatissimum (Flax)
Plantago psyllium (Psyllium seed)
Althea off. (Marshmallow)