Constipated Time s up. Dulcolax Medicated Laxative Suppositories can help get you going in 15-60 minutes. These comfort-shaped suppositories are medicated with the active ingredient bisacodyl for fast relief in minutes. As with any suppository Dulcolax medicated suppositories are for rectal use only; do not swallow. Looking for relief in 6-12 hours Try Dulcolax Stimulant Laxative Tablets for gentle relief. Trust the No. 1 doctor-recommended stimulant laxative brand for relief when you need it most. DIRECTIONS: Adults and children 12 years of age and over: 1 suppository in a single daily dose. Peel open plastic. Insert suppository well into the rectum pointed end first. Retain about 15 to 20 minutes; Children 6 to under 12 years of age: 1/2 suppository in a single daily dose; Children under 6 years of age: ask a doctor. Among OTC Stimulant Laxatives.