Dulcolax Suppository Mechanism of Action

Pharmacology: As a laxative that acts on the colon, bisacodyl specifically stimulates the natural evacuation process in the lower region of the gastrointestinal tract. Therefore, bisacodyl is ineffective in altering the digestion or absorption of calories or essential nutrients in the small intestine.
Bisacodyl (Dulcolax) is a locally acting laxative from the diphenylmethane derivatives group.
As a contact laxative, bisacodyl stimulates peristalsis of the colon and promotes accumulation of water in the colonic lumen which leads to stimulation of defecation, reduction of transit time and softening of stool.
The laxative effect of Bisacodyl (Dulcolax) occurs upon contact with the colonic mucosa where it stimulates the sensory nerve endings that results to increased peristaltic contractions of the large intestine to produce soft well-formed stools. This results in a stimulation of defecation, reduction of transit time, and a softening of the stool. It is a reversible reaction wherein colonic function would return to its normal condition after defecation occurs.
The tablets usually exert a laxative effect within 6-12 hours after intake. The suppositories usually take effect in about 20 minutes (range 10 to 30 minutes); in some cases, it occurs 45 minutes after administration.