When 19, I had a surgery prep for anal fissure, the order was given: "enemas till clear", they called it..
the first enema consisted of 2 quarts soapy water and was tolerated with some effort.
the second enema, an additional 2-quarts of soapy water, was given after not enough time to fully expel the first.
And finally after being allowed to drain what i could. another 2-quarts because not clear enough. was administered.
When the bucket had emptied its contents into my colon the nurse refilled it. and the second 2-quart filling began. As filling progressed the pressure became intense, I had never considered taking that much was even possible.
At this point i felt like i could burst or leak when the nurse announced it was all in me and that I needed to hold it for 10 minutes before being allowed to release the 4 plus quarts boiling in my guts.
THEN, Without warning the nurse wiggled the nozzle to remove it from my anus and it happened: The trigger was pulled on Intense waves of orgasmic contractions hit releasing a pulsing jets of semen and quick gushing spray of enema water before i could regain control.