





Colac | Taisho Pharmaceutical
A classic Japanese constipation medicine that works reliably for chronic and habitual constipation.
For these people and situations
Product overview
"Colac" is a leading Japanese constipation medicine manufactured and sold by Taisho Pharmaceutical. The active ingredient bisacodyl directly stimulates the large intestine to enhance peristalsis, effectively treating chronic and habitual constipation. Its unique 5-layer coating technology ensures the active ingredient does not dissolve in the stomach but acts only in the large intestine, with effects appearing the next morning (6 to 11 hours after taking) when taken on an empty stomach before bedtime.
Easy to use with a clear dosage of 2 tablets once daily for adults, this Class 2 OTC Drug has been widely trusted in Japan for many years for its efficacy against chronic and habitual constipation.
Product features
Directly stimulates the large intestine to promote bowel movements
Bisacodyl 10 mgActive ingredient bisacodyl stimulates peristalsis in the large intestine, enhancing reduced intestinal movement to support bowel movements. Effective for chronic and habitual constipation.
5-layer coating that does not dissolve in the stomach but acts in the large intestine
Unique coating technologySpecial 5-layer coating allows the active ingredient to reach the large intestine without dissolving in the stomach. Avoid taking within 1 hour of antacids or milk as the coating may dissolve.
Effect the next morning when taken before bedtime
Effect onset guideline: 6 to 11 hoursTaking before bedtime or several hours before expected bowel movement results in effect the next morning (6 to 11 hours after taking as a guideline) (individual differences may occur). Designed for those who want to regulate their morning toilet rhythm.
Easy-to-swallow pink small tablets
Adults: 2 tablets once dailyPink small tablets with a clear dosage of 2 tablets once daily for adults. Take tablets whole with water or lukewarm water without chewing. Damaging the coating may reduce effectiveness.
Active ingredient
| Ingredient name | Content (per 2 tablets) | Classification and action |
|---|---|---|
| Bisacodyl | 10 mg | Stimulant laxative ingredient |
[Additives] White sugar, talc, gum arabic, castor oil, methacrylic acid copolymer S, methacrylic acid copolymer L, corn starch, magnesium stearate, glycerin, titanium oxide, lactose, Red No. 3, carnauba wax, purified beeswax, macrogol
Indications and effects
Dosage and administration
Usually, adults take 2 tablets once a day before bedtime or several hours before expected bowel movement, swallowing without chewing with water or lukewarm water.
| Age | Dose per time | Number of times per day |
|---|---|---|
| Adults (15 years and older) | 2 tablets | One time |
| Under 15 years old | Do not take | |
・Take preferably on an empty stomach.
・Avoid taking within 1 hour after antacids (stomach medicine) or milk. (This medicine may dissolve in the stomach due to antacids or milk and not provide the expected effect.)
・Do not chew or crush the tablet; take it as is. (Damaging the special coating may reduce effectiveness.)
・Press the raised part of the PTP sheet firmly with your fingertip to break the aluminum foil on the back, then take out and take orally.
Comparison with Colac series
| Comparison items | [Colac] | Colac II | Colac Mg | Colac suppository type |
|---|---|---|---|---|
| Drug classification | Class 2 OTC Drug | Class 2 OTC Drug | Class 3 OTC Drug | Class 3 OTC Drug |
| Dosage form | Tablet (oral) | Tablet (oral) | Tablet (oral) | Suppository (rectal insertion) |
| Main active ingredients | Bisacodyl | Bisacodyl + DSS (dioctyl sodium sulfosuccinate) | Magnesium oxide | Sodium bicarbonate and anhydrous sodium dihydrogen phosphate (carbon dioxide generation) |
| Mechanism of action | Directly stimulates the large intestine to promote peristalsis (stimulant) | Two-component action: stimulation of the large intestine (bisacodyl) + moisture penetration into stool (DSS) | Draws moisture into the intestines to soften stool (non-stimulant) | Generates carbon dioxide gas in the rectum to promote intestinal movement (local action) |
| Indications and effects | Chronic constipation and habitual constipation | Relief of constipation and symptoms associated with constipation (head heaviness, skin troubles, abdominal bloating, etc.) | Relief of constipation and symptoms associated with constipation (head heaviness, skin troubles, abdominal bloating, etc.) | Constipation |
| Stimulation to the abdomen | May cause abdominal pain | May cause abdominal pain | Less likely to cause abdominal pain | Less likely to cause abdominal pain (local rectal action) |
| Dependency risk | Body may become accustomed with long-term use | Body may become accustomed with long-term use | Low risk of dependency | Avoid long-term continuous use |
| Onset of effect | 6–11 hours after use (varies by individual) | 6–11 hours after use (varies by individual) | Taken before bedtime for next morning effect (varies by individual) | About 10–30 minutes after use (fast-acting) |
| Target age | Ages 15 and up | Ages 15 and up | Ages 5 and up (with age-specific dosages) | Ages 12 and up |
| Recommended for | For those wanting a strong effect for chronic or habitual constipation | For those wanting to soften stools with moisture and have a strong effect with two ingredients | For those seeking a constipation medicine less likely to cause abdominal pain or concerned about hard stools | For those seeking fast-acting effects or who dislike oral medicine |
*This comparison is based on official information for each product. Effects may vary by individual. Please check the package inserts of each product before use.
❓ Frequently Asked Questions
Q When is the best time to take Colac?
A To help restore a regular morning bowel movement rhythm, it is basically recommended to take it before bedtime. The 5-layer coating ensures the active ingredient does not dissolve in the stomach but works effectively in the intestines, so taking it on an empty stomach is more effective.
Q Why should I not take it with antacids or milk?
A This product may dissolve in the stomach due to antacids or milk, preventing it from reaching the large intestine and reducing its expected effect. Avoid taking it within one hour of consuming antacids or milk.
Q Is it safe to take this product for a long time?
A Stimulant ingredients like bisacodyl can cause the body to become accustomed to them, reducing effectiveness over time. It is important to avoid long-term use. If symptoms do not improve after one week of use, stop taking the product and consult a doctor, pharmacist, or registered seller.
Q How should I differentiate between the different Colac series products?
A Colac is a stimulant laxative containing bisacodyl alone, suitable for chronic and habitual constipation. For those seeking a constipation medicine that is less likely to cause abdominal pain, Colac Mg (containing magnesium oxide) is recommended. For those wanting a richer formula with two active ingredients, bisacodyl and DSS, Colac II is suitable. It is also recommended to use these ingredients appropriately depending on your needs.
🌱 Brand Story
“Colac” is a leading constipation medicine brand in Japan, manufactured and sold by Taisho Pharmaceutical Co., Ltd. Its unique formulation uses a proprietary 5-layer coating technology to release the active ingredient bisacodyl only in the large intestine, a revolutionary approach supported by many users. The Colac series now includes Colac II, Colac Mg, Colac suppository type, and Colac Herb, offering a wide range of options to suit different constipation symptoms and preferences.
- Do not: take other laxatives while using this product. Also, do not take in large amounts.
- Consult a doctor, pharmacist, or registered seller before use: if you are receiving medical treatment, are pregnant or think you may be pregnant, or have severe abdominal pain, nausea, or vomiting.
- If severe abdominal pain, nausea, or vomiting occurs after taking the product, stop immediately and consult a doctor, pharmacist, or registered seller.
- If diarrhea symptoms persist or worsen, stop taking the product and consult a doctor, pharmacist, or registered seller.
- If symptoms do not improve after one week of use, stop taking the product and consult a doctor, pharmacist, or registered seller.
- Store in a cool, dry place away from direct sunlight.
- Keep out of reach of children.
- Do not transfer to other containers (risk of misuse and quality changes).
- Do not take the product after the expiration date.



























































































