I’ve taken 3 ½ quarts a few times while doing multiple enemas as an adult. Primary because, after my first three quart enema, I wouldn’t be completely empty during my second three quart enema. Giving me around 3 ½ quarts for my second and sometimes third enema of the day.
When my siblings and I were kids, our RN grandmother started giving us 3H enemas the summer I turned nine. Up until then, she only gave us a one quart soapy then a one quart rinse enema. The first time she gave me a 3H enema, it consisted of a two-quart soapy enema then a two-quart rinse enema. The soapy enema was given with an 18 - 24 inch colon tube and the rinse enema was given with a curved black douche nozzle.
The first time I took over two quarts, I was at my girlfriend's house and had finished giving her a couple of enemas. This was the first time we’d done enemas at her house using her mom’s equipment. As she was giving me the soapy enema, I had trouble near the end taking the full bag, but managed to finish. I didn’t think anything about it until the rinse enema, when I had the same trouble again. I managed to finish the bag a second time in a row having trouble at the end. I occasionally had trouble taking a soapy enema, but never had trouble taking a rinse enema, especially after taking a soapy enema first. It made me curious, so I looked in the linen closet for the box her douche/enema bag came in. I found the box, and sure enough, it wasn’t a two quart bag like we had at home, it was a 2 ½ quart bag.
I wouldn’t take over 2 ½ quarts until I was married many years later. My wife came in one afternoon with a newly acquired three quart pumpkin bag and wanted to try it out. So, she asked me, “can I try it out on you?” Looking at her, I said, “Sure. But I'm going to giving you one too.” She agreed, so we undressed each other, before going to the bathroom naked. I watched as she fixed a three quart salt and baking soda rinse enema for me. When she hung the bag up, I got in the knee chest position and over the next fifteen minutes, took the full three quarts. While I was expelling, she fixed another three quart rinse enema for herself. When I finished on the toilet, she got down in the knee chest position for her go at it. Like me, she was able to take the full bag, however, she did have a little trouble near the end. After our enemas, we got in the shower together and ended up having intercourse before getting out to dry off. This was the first of many three quart enemas my wife and I gave each other over the years.