Dulcolax 10mg Suppositories (12). DULCOLAX Suppositories contain a medicine called bisacodyl. This belongs to a group of medicines called laxatives.. DULCOLAX Suppositories are used for relief of constipation. This medicine does not help with weight loss. DULCOLAX Suppositories are also used in hospitals to clear the bowel before surgery, X-rays or other tests. DULCOLAX Suppositories stimulate the muscles of the bowel (large intestine), helping to return the body to its natural rhythm.