For me, the choice of laxative v. enema depends on what I'm trying to do….. get relief from being unable to poo or playing.
If it's the former and for some reason have not pood in a couple of days and just need a ‘little help’ to0 go without excessive straining, I'll take a full cap full dose of Miralax in the evening a couple of hours before bedtime and then a dose of Senna at bedtime, either ExLax pills or now the new laxative gummies. This usually results in a soft, formed, easy to pass, poo soon after breakfast. If this does not happen by lunchtime it's time for the bag, with my preference of nozzle being a soft red rubber Fr 28 colon tube inserted high. In general, I want complete relief, but gently and without discomfort. The combination of the nighttime laxatives and the morning enema, if needed, accomplishes this.
If the intent is play, things are quite different. I generally start with a liquid glycerin enema of about 1 Oz and retain until the urge to poo is intense, then evacuate. Then it's Coloclean time. Since it's hard to pee with the Coloclean speculum in and inflated, my preference is to be cathed with a Duette, connected to a bed bag. With the catheter in place, the Coloclean speculum is inserted and the balloon inflated. The enema series then starts and is usually clear water, water with Dulcolax, water rinse, water with baking soda, and finally coffee. Each of the enemas is retained as long as comfort will permit. The absorbed water is peed out continuously throughout the session which takes several hours.