Both are highly effective laxatives and have similar potential side effects.
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What Are the Main Differences Between Dulcolax and Miralax?
Dulcolax is the brand name for the OTC stimulant laxative containing the active ingredient bisacodyl.
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For the purpose of this article, Dulcolax and bisacodyl are used interchangeably.
Bisacodyl is a stimulant laxative that works directly on the nerve plexus of smooth muscles in the intestine.
Miralax is an osmotic laxative that attracts water into the colon by osmosis.
Both Dulcolax and Miralax are available as generic products.
Uses
Dulcolax can be used by children ages 6 years and older up through adults.
For children under 6, consult a healthcare provider.
Miralaxs manufacturer states that it can be used without a prescription by people 17 and older.
Adolescents and children under 17 can use Miralax with guidance from a healthcare provider.
Many pediatric gastroenterologists recommend Miralax for treating constipation in children.
How Long Do Dulcolax and Miralax Take to Start Working?
Dulcolax may cause abdominal discomfort, cramping, and diarrhea.
Side effects of Dulcolax appear to be dose-related, with higher doses more likely to cause side effects.
Who Shouldn’t Use Miralax or Dulcolax?
This table summarizes the doses for the different formulations available for Dulcolax and Miralax.
Effectiveness
Dulcolax and Miralax have not been directly compared to each other in clinical trials.
Both are effective at treating constipation.
Which Is Right for Me?
When deciding which OTC laxative to use, consider how quickly you want it to work.
Dulcolax tablets are usually taken at bedtime with the goal of producing a bowel movement the next morning.
You should also consider the ease of taking each of these medications.
Miralax is tasteless and colorless when dissolved.
It can also be mixed with any beverage, making it easy for children.
Some people may need assistance in administering the rectal suppository.
In clinical trials, more people reported side effects when they took a higher dose of bisacodyl.
Summary
Dulcolax and Miralax are OTC laxatives used to treat constipation.
Dulcolax is a stimulant laxative that improves bowel movements by boosting intestinal muscle contractions.
Miralax is a powder you mix with a beverage and needs one to three days before taking effect.
Both are well-tolerated and effective.
Deciding between Dulcolax and Miralax often comes down to personal preference and whether you need fast results.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).Constipation.
2021;33(10):e14123.
2016;7(2):274-282. doi:10.4292/wjgpt.v7.i2.274
DailyMed.Label: Miralax- polyethylene glycol 3350 powder, for solution.
DailyMed.Label: DULCOLAX LAXATIVE- bisacodyl suppository.
DailyMed.Label: DULCOLAX SIMULANT LAXATIVE- bisacodyl tablet, film coated.
Leung AK, Hon KL.Paediatrics: how to manage functional constipation.Drugs Context.
2021;116(6):1156-1181. doi:10.14309/ajg.0000000000001222
Dulcolax.Ducolax tablets.
2016;2016(8):CD009118.
