[6] Bisacodyl works by stimulating enteric neurons to cause peristalsis, i.e., colonic contractions.

The action of bisacodyl on the small intestine is negligible; stimulant laxatives mainly promote evacuation of the colon.

It is also available as a 1.25 US fluid ounces (37 ml) pre-packaged enema containing a 10 mg delivered dose of liquid bisacodyl.

Oral administration is known to produce no action for more than eight hours and then to work suddenly and relatively quickly.

A few hours after the initial evacuation, there can be a secondary action which will continue as long as there is unexpelled bisacodyl present in the rectum.