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Constipation medicine

1. Causes and onset mechanism of constipation

Stimulation of the stomach by food causes a contraction movement (gastric-colic reflex) throughout the colon, causing stool in the colon to move to the rectum. When the moving stool stretches the rectal wall from the inside, the pelvic nerves are stimulated and excitement is transmitted to the spinal cord and cerebrum, causing the urge to defecate (defecation reflex). Feces are excreted from the body by renewing abdominal pressure, peristalsis of the rectum, and relaxation of the anal sphincter. Constipation occurs when these defecation movements become abnormal.

Constipation is generally a condition of not having a bowel movement for three days or more, but bowel habits vary from person to person, and there may be no problems even if you defecate once or twice a week. On the other hand, even if you have a bowel movement every day. If you experience symptoms such as hard stools, a feeling of incomplete stool, abdominal pain, a feeling of bloating, and loss of appetite, you are considered constipated. Constipation can be broadly classified into functional constipation and organic constipation. Furthermore, functional constipation is constipation in which no organic abnormality is observed in the intestinal tract, but occurs due to intestinal motility dysfunction, and is classified into atonic constipation, spasmodic constipation, and rectal constipation.

  • Atonic constipation: As the movement and tone of the large intestine decreases, stool remains in the large intestine for a longer period of time, causing more water to be absorbed than necessary, causing the stool to become hard.

  • Spasmodic constipation: Occurs due to spasmodic contractions of the large intestine, which prevents effective transport of stool.

  • Rectal constipation: Even when stool reaches the rectum, the defecation reflex does not occur, causing the stool to stagnate and make defecation difficult.

2. Symptoms for which constipation medications are effective

Constipation treatment drugs are indicated for alleviating various symptoms caused by functional constipation, and their mechanisms of action can be broadly divided into four types.

  • A salt laxative that absorbs water in the intestinal tract through osmotic action and promotes intestinal peristalsis.

  • A bulking laxative that absorbs water and expands, stimulating the large intestine and promoting intestinal peristalsis.

  • A moisturizing laxative that lowers the surface tension of stool, making it soft and facilitating defecation.

  • A stimulant laxative that acts directly on the enteric nerve plexus to increase morning peristalsis and promote defecation.

For functional constipation (atonic, spasmodic, and rectal), first of all, the patient background:

①Eating habits (how many meals a day do you have) and meal content

②Lifestyle habits

③Exercise habits

④ Presence or absence of mental stress

⑤ Defecation status (hardness of stool and feeling after defecation)

⑥Abdominal symptoms

Check the following and improve your diet and lifestyle before choosing a laxative.

After that, choose a laxative.

If you experience sudden onset of constipation, thin or bloody stools, severe abdominal pain, or vomiting, seek medical attention.

>>Atonic constipation

It causes symptoms such as bloating, feeling of incomplete stool, loss of appetite, stiff shoulders, sensitivity to cold, and fatigue. It is the most common type of constipation, and is more common in women, the elderly, and people who have been bedridden for a long time. Causes include muscle weakness, lack of exercise, lack of water, and extreme dieting.

Indications: Salt laxatives and bulking laxatives are the first choice. Depending on the symptoms and effects, stimulant laxatives may be used in combination.

Other measures

① Make sure to have a regular diet and intake enough dietary fiber and water.

② Moderate exercise and abdominal massage.

>>Spasmodic constipation

The stool is often lumpy, like rabbit feces. In addition, after defecating hard stools, the stools become soft or muddy, and constipation and diarrhea often occur repeatedly. Pain in the lower abdomen after eating. or cause symptoms such as a feeling of incomplete stool. Triggers include mental stress (disturbance of the autonomic nervous system) and changes in the environment.

Indications: Non-irritating laxatives such as saline laxatives, bulk laxatives, moist laxatives. Do not use stimulant laxatives.

Other measures:

① Make sure to have a regular diet and intake enough dietary fiber and water.

② Relieve stress.

>>Rectal constipation

It becomes difficult to feel the urge to defecate. It is common in the elderly, people who have been bedridden for long periods of time, and people who have a habit of holding back their bowel movements (holding back their bowel movements due to pain from hemorrhoids, holding back their bowel movements due to shame, etc.). Excessive use of laxatives can also be a contributing factor.

Indications: Salt laxatives, bulking laxatives, stimulant laxatives, plus a selection of enemas.

Other measures:

① Make sure to have a regular diet and intake enough dietary fiber and water.

② Moderate exercise and abdominal massage.

>>Visiting a hospital

>Organic constipation

Constipation is caused by intestinal lumen stenosis that causes obstruction of passage during the opening, and includes ileus, colon cancer, and intestinal adhesions.If you have bloody stool, severe abdominal pain, or vomiting, seek medical attention. Have a medical examination.

Do not use laxatives as they may induce intestinal perforation.

>Constipation due to systemic disease

If the cause is diabetes, hypothyroidism, electrolyte abnormalities, depression, etc., treat the underlying disease and treat constipation.

>Drug-induced constipation

List of main drugs that cause constipation


Main mechanism

Medication (morphine, codeine phosphate hydrate, etc.)

Inhibition of intestinal motility

Anticholinergic drugs, antipsychotic drugs, antiarrhythmic drugs, antidepressants

Gastrointestinal tone-reducing effect

Acid drugs (aluminum preparations, etc.), iron preparations, bismuth preparations

Astringent action

Parkinson's disease drug

Peripheral muscarinic receptor blocking effect

Antihypertensive drugs (calcium channel blockers)

Decreasing effect on gastrointestinal motility


3. Actions and characteristics of constipation treatment drug ingredients




Effects, characteristics, drug efficacy comparison, etc.

Related Products


salt laxative

magnesium sulfate

magnesium oxide

magnesium hydroxide

Effect: Salts increase the osmotic pressure in the hot water pipes, causing water to move into the intestines, softening the stool, and increasing peristalsis.

Characteristics: Less addictive.

Caution: Patients with renal impairment

bulking laxative

Plantago Obata seed coat

Action: Absorbs water in the intestinal tract and swells, softening the stool. Expanding stool volume stimulates the intestinal wall and increases peristalsis. Characteristics: Dietary fiber, non-addictive.

Comparison: Maximum effect after 2-3 days of continuous administration.

Moisturizing laxative

Dioctylsodium sulfosuccinate (DSS)

Lowers the surface tension of stool through its surfactant action. Penetrates water into hard stools to soften them.

stimulant laxative



Action: The effect of intestinal bacteria in the large intestine causes it to act as a rain anthron, stimulating the Auerbach's nerve plexus in the large intestine and increasing peristalsis.

Warning: Addictive. Do not take it for a long time.

aloe extract

rhubarb extract

Sodium picosulfate hydrate

Action: Passes into the large intestine without being hydrolyzed in the small intestine, and is activated by the enzyme arylsulfatase derived from the large intestine flora. It is hydrolyzed into diphenols, stimulating the colon mucosa and increasing peristalsis.

Characteristics: It acts relatively slowly and rarely causes unpleasant symptoms such as abdominal pain.


The ingredients themselves directly stimulate the large intestine and increase peristalsis.

Caution: Because it is processed into enteric-coated tablets, do not take it at the same time as antacids or milk.

It is addictive. Do not take it for a long time

Chinese medicine


Characteristics: Easy to use for people with moderate to slightly reduced physical strength, and widely used to treat chronic constipation.


Characteristics: Used for people who have a lot of subcutaneous fat in their abdomen and tend to be constipated.


Characteristics: A relatively physically fit person who tends to be constipated. Used for people who suffer from bloated upper abdomen.


Characteristics: It is used for habitual constipation in people with moderate or slightly reduced physical strength, and is easy to use for elderly people and those who are weak after illness.

Herbal medicine ingredients


Effect: Relieves intestinal spasms and suppresses abdominal pain.

Butt Meishi

Adjust the function of the intestines.


Sodium bicarbonate/Anhydrous sodium dihydrogen phosphate

Action: Stimulates the large intestine by generating carbon dioxide gas in the intestine, promoting defecation.

Features: Suitable for rectal constipation.

NEW LECICARBON Suppositories



Action: Makes the intestinal wall slippery, stimulates the intestine, activates intestinal movement, and promotes defecation.



calcium pantothenate

Vitamin B1

Action: Adjusts intestinal function.

Vitamin B6

Effect: Improves rough skin caused by constipation.

Herbal medicine ingredients

Coix barley (Yokuinin)

malt extract

Effect: The gradual fermentation of maltose makes stools softer and easier to pass. Used for constipation in infants.

castor oil

Action: Stimulates the small intestine, activates intestinal movement, and promotes defecation.

4. Ingredients you should choose and ingredients you shouldn't choose


Choose an enema.

It is also suitable for children by adjusting the dose.


As a general rule, do not use on pregnant women. If it is unavoidable, start with a small amount of salt laxatives.

Start and choose a small amount of a colon-stimulating laxative (sodium picosulfate). Ta

However, if a large amount is administered, there is a risk of inducing uterine contractions, so it is necessary to visit a hospital.

>> Breastfeeding

Sennosides, senna, and rhubarb have been reported to pass into breast milk and cause diarrhea in infants, so they should not be used during breastfeeding.

Alternatively, refrain from breastfeeding if using.

If it is unavoidable to use, use pisacodyl or sodium bicosulfate, which does not pass into breast

>>Elderly (over 65 years old)

Bulgaric laxatives can also be used by the elderly.

Elderly rabbit fecesAsakogan is suitable for stool.

Wan Yang・suppositoriesis also suitable for use in the elderly by adjusting the dosage.

saltslaxativeof magnesiumformulationAvoid taking magnesium preparations for long periods of time, as taking them may increase blood magnesium levels.

>>Dialysis patients with a history of kidney damage

Sodium picosulfate, senna-derived drugs, and bisacodyl can also be used by dialysis patients. However, care must be taken when using it continuously.

Avoid taking magnesium preparations that are low in salts, as they may increase blood magnesium levels.

>>List of precautions for use with magnesium preparations

Medicinal effect




New quinolone antibiotics, tetracycline antibiotics

Inhibits drug absorption through chelate formation. Leave an interval of about 3 hours and do not take them at the same time.

antacids etc.

Calcium preparations etc.

There is a risk of milk-alkali syndrome (hypercalcemia: loss of appetite, itching, dry mouth, etc.) (in addition to calcium preparations, large amounts of milk may also cause milk-alkali syndrome)

Osteoporosis treatment drug

Active vitamin D3 preparation

Magnesium absorption may be increased, leading to hypermagnesemia (nausea, weakness, etc.).

Bisphosphonate preparations

Inhibits drug absorption through chelate formation.

Leave a gap of at least 30 minutes and do not take them at the same time.

cardiotonic drug

Digitalis preparation

Affects absorption and excretion of digoxin.

Anemia treatment drug

Iron supplement

Affects absorption and excretion of iron preparations.

5. Medication advice

>>Precautions when taking medication

It is recommended to drink plenty of fluids to get the full effect of the laxative.

Be careful with drugs other than bicosulfate sodium, as tolerance may increase with weekly use, weakening the effect, and causing further repeated use.

Many preparations containing bisacodyl are enteric-coated tablets, so do not take them with antacids or milk (drug efficacy will be reduced).

As a guideline, the medicinal effect takes about 6 to 10 hours to take effect, so it is most effective to take it before going to bed. However, since this varies from person to person, it is a good idea to record the time you take it and the time you defecate.

>>Side effects that require attention


Side effect information and countermeasures

Anthraquinone derivatives such as sennosides

If taken in large quantities for a long period of time, melanin-like pigmentation may be observed in the large intestine, spasms and atrophy of smooth muscles may occur, and constipation symptoms may worsen along with electrolyte imbalance.

Measures > Improve by discontinuing the drug.

Preparations containing licorice

Pseudohyperaldosteronism: edema, weight gain. Increased blood pressure, hypokalemia, hypernatremia, etc.

Myopathy: muscle pain, weakness, muscle weakness, etc.

Countermeasures: Stop taking the medication and visit a hospital. Avoid using drugs containing the same ingredients in the future.

>>Points to note in daily life

The basic idea is to eat three meals a day. (Eating on an empty stomach stimulates the gastrocolic reflex (the movement that occurs when food enters an empty stomach), so breakfast is especially essential.)

20-25g of dietary fiber per day. It is recommended to drink at least 1.5L of water.

Irregular bowel habits can lead to constipation, so defecate (sit on the toilet even if you don't have a bowel movement) at a set time after breakfast.

Weak abdominal muscles can lead to constipation, so train your abdominal muscles through moderate exercise (just enough to get a little sweaty).

Get enough sleep and try to reduce stress.

Provide the above guidance and understand that laxatives are a supplementary medication.

High-protein and high-fat foods increase the number of bad bacteria, so foods rich in dietary fiber (seaweed, mushrooms, green and yellow vegetables, beans, potatoes, root vegetables, fruits, etc.) and lactic acid bacteria, which feed the good bacteria, are recommended. Ingestion improves the balance of intestinal bacteria and helps prevent constipation.

Drinking a glass of water or milk after you wake up in the morning can stimulate your intestines and encourage bowel movements.

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