Fast acting, reliable relief within 5-20 minutes: Fleet bisacodyl enema provides fast relief from constipation and can be used for bowel cleansing before rectal examinations. Bisacodyl is the active ingredient that directly stimulates the intestine to increase rhythmic action that pushes feces through the bowel. Easy-to-use, disposable squeeze bottle with a soft, pre-lubricated Comfortip. Fleet - - bisacodyl enema is sodium phosphate-free and latex-free.