Hi there,
There are lots of threads on the forum about anal douching - you're sure to find lots of useful information there!
There's also an easy-peasy douching guide on the LoveHoney Blog too.
The problem you are experiencing could be due to two things:
You are inserting the douche too far and it's hitting the curve of your rectum, which will block the flow of water.
Or gravity is making it exceptionally difficult to get the water up and out of the bulb.
In either case, make sure that you fill the bulb right to the top with clean, luke-warm water, position yourself comfortably then insert the tip gently only one or two inches. This will get it past both sets of sphincter muscles and allow it to easily empty the liquid into the rectum.
Then, using two hands for extra pressure, slowly squeeze the bulb g r a d u a l l y . This will dispense the water safely and evenly.
Make sure that you keep the bulb squeezed as you withdraw it to prevent the douche from sucking any of the water back in.