What Is Dulcolax? Uses, Dosage, and What You Need to Know in 2026

Dulcolax is one of the most recognizable laxative brands in the world — but many people aren't sure exactly what it does, how to use it correctly, or what to watch out for. This guide covers everything you need to know about Dulcolax in 2026: what it is, what it's used for, how to take it, and when not to.

What Is Dulcolax?

Dulcolax is the brand name for bisacodyl, a stimulant laxative that has been in clinical use since the 1950s. It belongs to the diphenylmethane chemical family and works by directly stimulating the muscles of the large intestine to contract, moving stool toward the rectum. It also prevents the colon from absorbing too much water, which helps soften the stool.

Dulcolax is available over the counter without a prescription in the United States. It is not a controlled substance. The same active ingredient is sold under many names, including Correctol, Fleet Bisacodyl, Bisac-Evac, Ex-Lax Ultra, and numerous store-brand generics.

What Is Dulcolax Used For?

Dulcolax has two main approved uses:

Occasional constipation: The most common use. Dulcolax provides relief from infrequent or difficult bowel movements. It is intended for short-term use only — no more than 7 days.

Bowel preparation for colonoscopy and surgery: Bisacodyl tablets are commonly included in colonoscopy prep kits (e.g., the HalfLytely kit) to clear the colon before a procedure. Suppositories are also used pre-operatively.

Common off-label uses include:

Neurogenic bowel management (spinal cord injury, multiple sclerosis)

Opioid-induced constipation (as part of a multi-drug bowel regimen)

Post-surgical bowel management (when oral administration is resumed)

What Forms Does Dulcolax Come In?

Delayed-release oral tablets (5 mg): The most commonly used form. Must be swallowed whole — do not chew or crush. Works in 6-12 hours.

Rectal suppositories (10 mg): For faster relief or when oral administration isn't possible. Works in 15-60 minutes.

Rectal enema (10 mg): Fastest onset of all forms. Works in 5-20 minutes.

Dulcolax Dosage: How Much Should You Take?

Standard dosing for occasional constipation:

Adults and children 12+: 1-3 tablets (5-15 mg) orally once daily, or 1 suppository (10 mg) rectally once daily as needed.

Children 6-11 years: 1 tablet (5 mg) orally once daily as needed.

Children 2-5 years: Suppository form only (5 mg pediatric suppository). Oral tablets are not recommended under age 6.

Important: Do not take more than 1 dose (in any form) in 24 hours. Do not use for more than 7 days without medical guidance.

Key Tips for Taking Dulcolax Tablets

Swallow whole with a full glass of water. Do not chew, split, or crush.

Do not take within 1 hour of dairy products (milk, yogurt) or antacids. These dissolve the tablet's enteric coating and can cause stomach irritation.

Take at bedtime for a morning bowel movement (6-12 hour onset).

Stay hydrated — drink plenty of water throughout the day.

Who Should Not Take Dulcolax?

Do not use Dulcolax if you have:

Severe abdominal pain, nausea, or vomiting

Signs of appendicitis

Known or suspected bowel obstruction or perforation

Ulcerative colitis or toxic megacolon

Known allergy to bisacodyl

For more on how bisacodyl works at a biological level, see our article on Dulcolax's mechanism of action. If you're having trouble finding Dulcolax near you, medfinder can help you locate it at a pharmacy near you.