I have a friend, Valarie, who would come visit me on the east coast and in return I would visit her in Los Angeles... about twice a year..
Generally we would go to New York City in hopes of going to a BDSM club and find willing participants to join us. On one occasion we thought we had a playmate, but she chickened out on us on the way back to the hotel. So once at the hotel Val is really horny and we start doing enemas. It's ladies first, and so we start, but each time she finishes she wants another. She took at least 5, from large volume enemas to one where the urge hit after only getting a pint or so in. The last enema was one of those where she emptied the bag and had me pour more water into it! She took over 3 quarts.
Then it was my turn, but it was very late, and Val fell asleep while I was expelling.
Next morning we got up very late, had a nice breakfast, and took a taxi back to Teterboro Airport, Val used to fly into Baltimore-Washington International airport, I'd meet her at the executive terminal and fly us to New York. Val had a life-long friend in Baltimore, so she would stay there a day or two as well visiting me for playtime.
It was a low overcast day, so an Instrument Flight was in order, and while I'm paying for fuel and the rent-a-car, and getting a weather briefing Val went to the to empty her bladder before we left. When she came back she said, what a surprize she just got, she said when she started to pee, the urge hit her and she must have expelled at least a quart of enema that had been resting comfortably inside her for about 8 hours.
I only had one surprise I wasn't prepared for, on a solo business trip to NYC, as I used to do I would visit Belle Du Jour, I always gave one and then got one (with a happy ending).. I thought I was fine, but hadn't gone far before the urge hit, I walked from lower Manhatten to Midtown with quite an urge! But I made it, and in the end found the "ordeal" rather exciting, and like my friend Val, I'm pretty sure I walked the distance while holding about a quart..