Bag or bulb? Either one is great but one holds an edge over the other.
Commonly, the bulb syringe is associated with enemas of convenience, quick enemas, enemas requiring small volumes. My mom knew differently. An uncommon Klysmo, she told me often that "if a little is good, a lot is better." Her policy was that the bulb syringe should be refilled as many times as necessary in order to give a "nice soapsuds enema." She was onto the erotic appeal of the bulb.
Although refilling to increase enema size gives the bulb syringe a boost in terms of anal intimacy, the enema bag remains a more powerful fetish object. The sight of a swollen, rigid enema bag with its large volume of fluid that can continuously be injected, a bonnet of white soapsuds at its neck, hanging eye stretched by the weight of its soapy load, certainly grabs the attention of a person about to receive a bag enema.
Then there is an S and M connection. S and M devices always evoke deep emotional responses for some reason. Compared to the bulb, the enema bag presents itself as more of a device, an instrument designed to administer more than just a simple enema.
Where the enema bag surges ahead of the enema bulb is in the availability of accessories and the variations that accessories create. Enema nozzles of various shapes, widths, lengths, and colors are available. Think about that penis shaped nozzle and its immediate association with anal sex. Think about that 36-inch colon tube that can be attached to reach deeply into the colon. Think about attaching a retention nozzle to the enema bag with its devious applications. A Higginson bulb can be paired with the enema bag for a surging effect.
Bag or bulb? It is difficult to choose. StephenS and Dave44123 make the decision even harder by their ideas for bulb use in combination with the bag to slyly inject special effects. But if I could only have one, it would be the enema bag.