Purge and purgatives

The purge is a medicinal substance that can promote or accelerate the evacuation of feces. Traditionally, the term has been reserved for remedies with an intermediate intensity of action between the milder ones (laxatives) and the so-called cathartic or drastic purgatives. This classification is scarcely used today, as very often the intensity of the effect depends more on the dose administered than on the intrinsic activity of the drug. In light of all these considerations, the term purgative is increasingly used as a simple synonym of laxative.

The indications in favor of the purgatives are limited; in most cases, in fact, constipation can be corrected by simply increasing the intake of liquids and fibers, and intensifying physical exercise. When obstinate constipation is due to important underlying causes - such as anorectal pathologies (haemorrhoids, rhagades, rectocele, etc.), nervous diseases, drugs or functional pathologies that affect the intestine (colitis, diverticulitis, etc.) - it is necessary to focus on treatment of causes rather than symptom constipation.

Other times, especially in women, the problem stems from the inability to completely relax the pelvic floor muscles that close the anal canal, or from the protrusion of the rectal walls towards the vagina at the time of exertion. Also in these cases it is necessary to treat the causes through surgical or behavioral interventions of education to defecation, since laxatives are often poorly tolerated or effective only at high doses. Purgatives, therefore, become necessary only on a few occasions, including the preparation for particular diagnostic or surgical procedures, the prevention of efforts for defecation and softening of feces (for example in the presence of hemorrhoids or post-infarction). The occasional ingestion of a purgative should not be demonized, but should be condemned for habitual or frequent use, which can lead to phenomena of dependence or serious side effects, especially when it is the result of self-prescription.

Traditionally, purgatives are classified into groups according to the prevailing mechanism of action. Also in this case there is some confusion, since a purge can produce the laxative effect sought through multiple actions.

GUY	MECHANISM OF ACTION	EXAMPLES
Purgatory lubricants	They lubricate the fecal mass and the walls of the intestinal lumen. The time of onset of action is around 6-8 hours.	Vegetable oils (sweet almond oil), vaseline oil or liquid paraffin).
Purgatory irritants, stimulants	Active ingredients, irritant or toxic, which abnormally stimulate intestinal motility and secretion. The evacuation of the faeces is thus accelerated. Of all, the most abused purgatives are by far. Generally it is advisable to take them at night before going to bed since they have an effect latency of about 6 - 8 hours.	They are the most numerous group of purgatives and include all the anthraquinone drugs (senna, aloe, rhubarb, frangola, cascara), castor oil, bisacodyl, phenophthalein, sodium picosulfate.
Purgatory mechanical	They retain water in the stool, increasing its volume and causing a mechanical distension of the colon that promotes motility. The effectiveness of these compounds is not immediate and may take up to a few weeks of therapy before they can be appreciated.	Fibers (bran, psyllium, linseed, mucilage, methylcellulose, glucomannan, policarbofil, etc.). The use of fibers must always be accompanied by adequate water intake, otherwise the symptoms will worsen.
Purgatory osmotic	They increase the osmotic pressure in the intestine, attracting water from the tissues towards the inside of the enteric lumen. The result is rapid: poltaceous feces of greater volume or consistency frankly aqueous can be eliminated already after 5 or 6 hours from the assumption, or 2-3 hours in the case of cathartic dosages widely used in order to empty the intestine before surgical interventions, radiological and endoscopic examinations.	Sodium sulfate; Magnesium sulphate; Magnesium hydroxide; Sodium and potassium tartrate; Some laxative foods, such as tamarind, cassia and dried prunes. Lactulose, lactose, polyalcohols (sorbitol, mannitol, glycerol), polyethylene glycol.

Side effects of purgatives

Laxative drugs are widely used and often abused by the general population, because they are considered safe and easily available without a prescription. For this reason, abuse and self-prescription are the main problems, especially in the presence of underlying pathologies and simultaneous intake of other medicines.

Below is a list of the main side effects of purgatives, which is necessary to make the reader aware of the topic and refer him to a preventive medical consultation.

Purgatives capable of promoting increased stool volume do not generally give serious side effects and above all produce poor systemic reactions. These substances, however, must always be taken with an adequate water supply, to avoid hardening of the stool which could lead to intestinal obstruction and aggravation of constipation. Subjects with gastrointestinal ulcers, stenoses or adhesions should avoid their use. Gastric swelling, meteorism, flatulence and abdominal tension are the most common symptoms of overdose. Many of these substances interfere with numerous drugs, limiting their absorption; psyllium can cause IgE mediated allergic reactions.

The side effects of saline osmotic laxatives (magnesium sulfate, magnesium hydroxide and sodium salts) derive from the fact that a small percentage of the salts is absorbed in the systemic circulation, causing more or less marked hydro-electrolyte imbalances. In this regard, hypertonic solutions are the most dangerous, especially for newborns and patients with kidney and hypertension problems. Polyethylene glycol, on the other hand, is generally well tolerated because it does not alter the patient's water and electrolyte balance.

Castor oil can cause damage to the intestinal mucosa, stimulate uterine contractions (contraindicated in pregnancy) and in the long term cause malabsorption. Vaseline oil can irritate the rectum and anal sphincter, and, if used for a long time, malabsorption of fat-soluble vitamins.

Prolonged use of stimulant laxatives can lead to a deterioration of intestinal function, making the colon muscles increasingly spastic and unable to contract. The abuse of anthraquinolonics can cause colon melanosis.

Finally, we remind you that after a vigorous defecation induced by the purge a time interval of a few days is needed before the waste necessary for a subsequent defecation accumulates in the intestinal tract. This condition of false constipation should by no means be understood as an abnormal phenomenon and in no way justifies a new intake of purgatives.

When is purge necessary?

For a rational treatment of constipation it may be useful to apply with rationality the following intervention strategy: respect a precise schedule of evacuations → do not postpone defecation when the stimulus arises → avoid sedentariness → limit stress as much as possible or find a way to vent accumulated tensions → follow a balanced diet with high residue (rich in plant foods and whole grains) → carefully chew food → consume meals at regular times, breakfast included) → limit alcoholic content → take abundant quantities of liquids distributed during day → during the evacuation take a "Turkish" position by placing a rise under the feet so as to bring the thighs closer to the chest → try to use the purge as less frequently as possible → start eventually with the volume laxatives, lighter but from the slower action → if frequent one becomes necessary Purgative intake contact the specialist.