Pharmacology: Bisacodyl is diphenylmethane stimulant laxative used for the treatment of constipation and for bowel evacuation before investigational procedures or surgery. Its action is mainly in the large intestines and it is usually effective within 6 to 12 hours following administration by mouth and within 15 to 60 minutes following rectal administration. Bisacodyl tablets should be swallowed whole and should not be taken within one hour of milk or antacids.
Pharmacokinetics: Following administration of bisacodyl by mouth or rectally, it is converted to the active desacetyl metabolite bis (p-hydroxyphenyl) pyridyl-2-methane by intestinal and bacterial enzymes. Absorption from the gastrointestinal tract is minimal with enteric-coated tablets or suppositories; the small amount. Absorbed is excreted in the urine as the glucuronide. Bisacodyl is mainly excreted in the feces.