Bisacodyl and Dulcolax: Same Active Ingredient, Same Medication
Yes, bisacodyl is the same as Dulcolax - they are identical, as Dulcolax is simply the brand name for the stimulant laxative bisacodyl. 1
Understanding Bisacodyl/Dulcolax
Bisacodyl is a diphenylmethane stimulant laxative that works through a dual mechanism:
- Active metabolite: Both bisacodyl and sodium picosulfate (SPS) are converted in the gut to the same active compound - bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM) 1, 2
- Mechanism of action: BHPM acts directly on the colonic mucosa to stimulate peristalsis and increase secretion 1
- Conversion process: Bisacodyl is converted to BHPM by intestinal and colonic mucosal deacetylase enzymes 1
Formulations and Administration
Bisacodyl/Dulcolax is available in multiple formulations:
- Oral tablets: Typically 5-10 mg enteric-coated tablets 1, 3
- Rectal suppositories: 10 mg strength 1, 4
- Onset of action:
- Oral tablets: 6-12 hours
- Suppositories: 30-60 minutes 1
Dosing Recommendations
- Initial dosing: Clinical practice often starts with 5 mg orally, although clinical trials typically used 10 mg 1
- Titration: Dose can be adjusted based on response 3
- Duration: Primarily recommended for short-term or rescue therapy rather than long-term use 1
Efficacy
Bisacodyl has demonstrated effectiveness in treating constipation:
- Bowel movements: Significantly increases complete spontaneous bowel movements (CSBMs) and spontaneous bowel movements (SBMs) per week compared to placebo 1, 5
- Stool consistency: Improves stool consistency on the Bristol Stool Form Scale 1, 5
- Comparative efficacy: Recent meta-analyses suggest bisacodyl may have similar or superior efficacy compared to other laxatives for chronic constipation 6
Side Effects and Precautions
Common adverse effects include:
- Diarrhea: Occurs in approximately 53.4% of patients taking 10 mg (vs 1.7% with placebo) 1
- Abdominal pain: Occurs in approximately 24.7% of patients (vs 2.5% with placebo) 1
- Timing of side effects: Most adverse events occur during the first week of treatment 1
Contraindications
Bisacodyl/Dulcolax should not be used in patients with:
- Ileus
- Intestinal obstruction
- Severe dehydration
- Acute inflammatory conditions of the bowel 1
Clinical Pearls
- Antibiotics impact: Antibiotics may potentially decrease the efficacy of sodium picosulfate (which shares the same active metabolite) by affecting the gut bacteria needed for conversion 1
- Long-term use: The long-term effectiveness has not been well-studied in adults, though pediatric data suggests it may be safe and effective for refractory constipation 1, 7
- Combination therapy: Can be used as part of a stepped approach to constipation management, often added when a single laxative is insufficient 3
Bisacodyl/Dulcolax remains an important option in the management of constipation, particularly as a short-term or rescue therapy when other approaches are insufficient.