This was actually during an S & M scene we did about ten years ago.
A year or two after a particularly severe scene I subjected my husband to over the President's Week vacation when our daughters were at their friend's house for a sleep-over, my husband had a chance to give me a couple of enemas while I was restrained. Part of the scene required that I had to be extremely quiet because this time the girls were home, and the only excuse we could give for not answering a knock on our bedroom door would be that we were having sex at the moment.
The first thing he did was bend me over his knee and insert a 750 cc double balloon rectal catheter and pump it up. Then he put on leather wrist cuffs and took a rope and tied my bound wrists to a hook we have in the bathroom ceiling, which prevented me from walking or bending over. To make matters worse, he applied some tight nipple clamps with about 4 ounces of weight on each one, which isn't a lot, but it ensures you're paying attention. Then he started the enema. He let about 2 to 2 1/2 quarts flow into me while I was standing there. I really felt my belly get tight and had a lot of pressure down on my rectum. He forced me to quietly stand there and hold it for about twenty minutes to make sure everything got loosened up inside my colon, after which he let me expel it. When that was over, I discovered I was in for more. He brought out a plastic drop cloth (we always keep several around the house for potentially messy scenes) and laid it out over the bathroom floor, and had me lie down on it. Instead of using a double balloon rectal catheter, he took a 48 Fr colon tube which he inserted about 18-20 inches. I could tell the tube made it into my transverse colon because I could feel it with my hands under my ribcage. He duct-taped the tube to my inner thigh to keep it in place, stood me up and re-tied me to the hook in the ceiling. This time I got two quarts but now I had to hold it in myself while the colon tube remained inserted. Needless to say, I was not pleased with this prospect since I knew that cleaning any leakage would be my responsibility. The nipple clamps were beginning to hurt and he threatened to put a bunch of clothespins down my inner thighs if I complained any more, which after not too long, I did. Well, holding the enema with my stomach churning and having the clothespins and nipple clamps proved too much for me, and I had an accident. Not a big accident, but I was a mess and it was a good thing the drop cloth was there. Any enema accident is more than I ever want to deal with. He made me stand there, soiled down my legs and standing in a puddle of brown fecal water for about ten more minutes until I was released and allowed to go to the toilet and shower. That was a messy night for me.
The rotten bastard (I do love him) said he was glad he was able to "make me experience the mess" because of the time a year or so before, when I had him tied up in bed after an enema, and he said he had to "go". I told him it was probably just gas since the enema wasn't very large and it was over two hours earlier and that he should just fart it out. Well, it wasn't just gas, and it had a lot of mucusy secretions from the concentrated glycerine and water enema I had given him, and I made him wait for me to come clean him up--I didn't let him get up to do it himself. After he was cleaned up, I spanked him for making a mess. This time I got my comeuppance. I guess all's fair in love and S&M!