Yes, bisacodyl is available over the counter in the United States and most other countries. You can buy it at pharmacies, grocery stores, and online without a prescription. It’s sold under brand names like Dulcolax, Fleet Bisacodyl, and various store-brand generics, in both oral tablet and rectal suppository forms.
How Bisacodyl Works
Bisacodyl is a stimulant laxative. Once swallowed, enzymes in your intestines convert it into an active form that stimulates nerve endings in the lining of your colon. This triggers the muscular contractions (peristalsis) that push stool forward. At the same time, it increases the amount of water in your stool, making it softer and easier to pass.
Oral tablets are coated with an enteric layer designed to survive your stomach acid and dissolve only once they reach the intestines. This is why timing and what you take with the tablet matters, which is covered below.
Forms and Dosages
Bisacodyl comes in two OTC forms: oral tablets (typically 5 mg each) and rectal suppositories (5 mg or 10 mg). They work at very different speeds.
Oral tablets are usually taken at bedtime so they produce a bowel movement the next morning. Adults and children 12 and older can take one to three 5 mg tablets (5 to 15 mg) as a single daily dose. Children ages 6 to 11 should take only one tablet. Children under 6 need a doctor’s guidance before using bisacodyl.
If you haven’t used bisacodyl before, start with the lowest dose of one 5 mg tablet. If that isn’t enough, you can increase to two tablets (10 mg) the next time. Higher doses are more likely to cause cramping and nausea, so starting low makes sense.
Suppositories work faster, typically within 15 to 60 minutes, and are used in the morning rather than at bedtime. The usual adult dose is one 10 mg suppository. For children ages 4 to 9, a 5 mg suppository can be used, but only on a doctor’s advice.
What Not to Take With It
Avoid antacids, milk, and other dairy products within one hour of taking bisacodyl tablets. These raise the pH in your stomach, which can dissolve the enteric coating too early. When the coating breaks down in the stomach instead of the intestines, the drug causes stomach irritation, nausea, and cramping. Swallow the tablets whole with plain water, and don’t crush or chew them for the same reason.
Common Side Effects
The most frequent side effect is abdominal cramping, though most people find it mild. Other possible effects include bloating, nausea, and stomach discomfort. These tend to be more pronounced at higher doses. In one study comparing a 10 mg dose to a higher dose, patients on the lower amount reported significantly less cramping and nausea.
Suppositories can temporarily make the rectal lining appear inflamed, which is harmless and resolves on its own. Occasional fecal incontinence has also been reported, so plan your first use for a day when you’ll be near a bathroom.
Risks of Long-Term Use
Bisacodyl is meant for short-term, occasional relief of constipation. Heavy or chronic use can deplete potassium and other electrolytes, which in rare cases has led to muscle breakdown (rhabdomyolysis). There are also concerns that prolonged daily use of any stimulant laxative can lead to a sluggish, weakened colon that becomes dependent on the drug to function. Short courses at standard doses don’t carry these risks in studies, where serum electrolytes remained unchanged.
If you find yourself reaching for bisacodyl regularly for more than a week or two, that’s a sign to look into the underlying cause of your constipation rather than continuing to manage the symptom.
Who Should Avoid Bisacodyl
Bisacodyl is not safe for everyone. You should not use it if you have:
- A bowel obstruction or suspected blockage
- Severe stomach pain with nausea or vomiting, which could indicate appendicitis or another serious abdominal condition
- Signs of dehydration, such as dark urine or urinating much less than usual
- Inflammatory bowel disease, including ulcerative colitis or Crohn’s disease
- A motility disorder where the muscles of your bowel can’t move food along normally
If you’re using suppositories specifically, avoid them if you have anal fissures or cracked skin around the anus, as the suppository can worsen irritation in damaged tissue.
Use During Pregnancy and Breastfeeding
Bisacodyl is generally considered safe during all three trimesters of pregnancy when used occasionally at standard doses. Prolonged or high-dose use during pregnancy warrants a conversation with your provider, and alternatives may be preferred in that case. During breastfeeding, bisacodyl is considered safe to use.