Dulcolax 5mg tablets contain bisacodyl and provide effective overnight relief from constipation. This pack contains 40 coated tablets that work within 6-12 hours to provide dependable constipation relief. Dulcolax is a stimulant laxative medication containing 5mg of bisacodyl per tablet. The coated tablets are designed to provide overnight relief, typically working within 6-12 hours after taking. This package contains 40 tablets. As with all medications, this should be taken according to the recommended dosage and instructions.