Bisacodyl USP 5 mg. Gentle Predictable Overnight Relief. #1 Doctor Recommended Brand Among Stimulant Laxatives. Easy-to-swallow comfort coated Dulcolax Tablets are gentle enough for sensitive stomachs yet strong enough for effective overnight relief. Trust Dulcolax Tablets to relieve constipation in 6 to 12 hours. Dulcolax Tablets are convenient to use overnight or whenever you need effective relief from constipation. . Use: for temporary relief of occasional constipation and irregularity • this product generally produces bowel movement in 6 to 12 hours.