At my age (late 70's) I have prostate problems so I use a large shampoo bottle as a massager every evening in the shower. This has interesting side effects, apart from the pleasurable sensations of the actual massage.
I also take a stool bulking agent (psyllium husk powder) every day to prevent constipation, to which I am prone. After an enema clean out (I describe my standard procedure elsewhere on this site), there is no fecal matter at all in my rectum; but after four days, there is. To keep the prostate massage clean, I first work the bottle into my arsehole to loosen it but not touch the turd sitting in my rectum. Then I put about a tablespoonful of water into a bulb enema syringe. kneel in the knee chest position (which renders the descending colon nearly vertical), and inject the water with a lot of air to distend rectum and colon. I then reinsert the shampoo bottle (it's about 63 mm or 2 1/2" in diameter and nearly 200 mm - almost 8") fully until the cap is within my arsehole. This drives the turd right away from my prostate; in fact, out of the rectum entirely. I can then do my massage and there's little if any fecal matter on the bottle when I'm finished because it doesn't stick to the wet surface.
At my age I don't eat a lot, but I'm still active and often don't get enough to drink. Added to this I fast one day a week. The net result is that my descending colon fills progressively but without any 'urge to go' as there's nothing in my rectum most of the day. Each day the turd is pushed back into the descending colon. I like the sensation of being able to feel the growing mass through my abdomen, but not have any feeling of fullness from beneath. Also I can feel both ends of the turd plug, find the lower end and push it further up me after I get into bed. Later, after about six days, I can also locate its upper end and squeeze both towards each other so as to compress it longitudinally and expand it laterally. It gets shorter but fatter!
Last time I did this, various things prevented me from taking my clean out for eleven days. There was still no fecal matter in my rectum on Wednesday when I took the enema (5 tablespoons of salt, 3 of Epsom salt in 5 litres of water). I held that for ten minutes of great cramps. Our modern low flow toilet blocked with the first expulsion of solids, and the bowl began to fill up as the most enjoyable expulsion continued. So great was the amount of water and backed up waste that eventually I noticed my balls were getting warmer! They were dangling in the rising tide and I found this strangely erotic. Still, the mass didn't move in the toilet bowl! It did not finally overflow, but the bowl barely contained it.
This does not much matter as our bathroom is a wet room, and the shower is only a step away. I cleaned my rear and my balls and penis (yup, he also got wet), and poked with the toilet plunger to clear the blockage. No luck. I dared not flush, as the level in the bowl was already up to the rim. There was nothing for it but to plunge my hand into the mess and force it round the trap. I'm not (I think) into scat, and it was a real effort to shove the very large stiff mass through the water trap, but I was kind of amazed at how much stuff had come out of me; pleased, too,because I'd enjoyed getting rid of it. Finally my efforts were rewarded with a prolonged sigh as the blockage shifted, and the liquid level in the bowl returned to normal.
The following rinse enema of 8 litres was entirely without incident, except for the total emptying of my colon without the retention of any water at all! And, of course, the sensation of lightness and well being was tremendous.
Would I do this kinky thing again? You bet; but I have to find another way to unblock the toilet! I might just give the toilet itself a colon tube enema straight from the shower hose, right into the stuck mass? Watch this space!
Johnny