@Chase
Dulcolax, and many other laxatives, work the same given orally or rectally. It's just that the enema route works a lot faster.
Dulcolax enemas are easy to do and really make someone cramp and poo.
The easiest way to prepare one is to dissolve one or two Magic Bullet suppositories in a bag of warm water. These are water soluble. Ordinary Dulcolax suppositories won't dissolve in water (although they will dissolve in warm mineral oil to make a very powerful enema that simply cannot be held when it works. It's messy though.)
You can also make a Dulcolax enema by crushing up the 2 to 4 pills or dissolving them in a baking soda solution.
As to taking the enema, it can be tricky. A bicacodyl enema has to be given slowly enough to not cause camps as the solution is going in, but fast enough so that the bisacodyl's laxative effect doesn't really get going before the bag is empty. For me a disposable 1500ml bag, full of warm water with one Magic Bullet suppository dissolved in it, is about right. The hose/nozzle gets inserted about 6" to 8" and the bag is hung about 2 feet above the point of injection. When the clamp is opened, all the solution goes in within about 5 minutes. After about another 5 to 10 minutes, the solution gets VERY hard to hold and a mighty poo soon happens.
The strength of the enema can be increased by adding a bit of Ivory or Castile soap to the enema solution. Note the combination makes a very, very powerful enema.