The Anal Douche from Cal-Exotics is a basic, but well built bulb douche. It is sturdy, large and it even features a glow in the dark tip (actually could be more useful than you think). The tip slides in effortlessly, due to its slender, smooth design. Once in place, the bulb can be squeezed to spurt ounce after ounce of warm or cool fluid into your (or your lover's) bottom. Douches are great for anal prep (obviously), but can also be great for anal training in general - some people even load them up with a bit of lube prior to heavy anal interaction.
FYI, the bulb holds around 7 oz. of fluid.