Tammy,
It just depends upon three things: the enema solution, how much volume, and what is it that I'm doing doing during an enema.
The Enema Solution: Baking soda, coffee (sometimes in combination) and salt water enemas generally allow me to have the longest hold times depending upon the other two factors.I can and have taken 4.0 liters of baking soda, coffee, baking soda /coffee, salt, and coffee / salt enemas and been able to hold them for 60 minutes or more. Plug in an inflatable nozzle. The lower the volume (say 3.0-3.5 liters), the easier it is to hold these solutions for a longer period of time. Once above 4.5 liters, the retention time shortens dramatically even though these are the easiest solutions to hold (though I did hold more than 4.0 liters of coffee for more than 90 minutes one morning while chatting with a friend. Once I get beyond the first few hard contractions with these solutions, the peristaltic contraction intensity tends to drop dramatically for quite a while.
Soapy enemas can be rather difficult to hold, particularly when they are strong. I define strong as more than 15 grams of Ivory soap per liter or more than a tablespoon of liquid soap per liter. These usually have a peristaltic contraction reaction within the first few minutes of introduction, but if I can ride those out, I can usually get at least 15 minutes of retention for these soapy solutions. A hold time of up to 30 minutes is possible with weaker solutions. And the toughest ones I've tried is soap/glycerin combinations. Holding 20 minutes is outstanding (10-15 minutes is more typical, though once I was able to break the one hour barrier but only with the help of someone trying to coach me through it once I got through the initial worst part). I generally limit soapy enemas to a maximum of 3.5 liters, though lower volumes are more typical. I want the enema to fill me enough to get spread throughout my colon and give the muscles the colon space to contract and churn the contents.
The Enema Volume: The larger the volume, the harder it is to hold. I can hold a 2.5 liter enema longer than a 3.0 or 3.5 liter enema, generally speaking. A 4.0 liter enema for a shorter period than a lesser volume. Times start getting appreciably shorter once 5.0 liters is taken in and the few 6.0+ liter enemas I've taken aren't associated with long hold times. Maybe 10-15 minutes at somewhere around 5-liters probably 5-10 at 6-liters. Please note that while a couple of my bags are capable of holding 6.0 liters and I may fill them to that volume, I only take what I am comfortable holding. And 6-liters is a massive amount of liquid at 2.2 pounds per liter. I can say the look on me is early male pregnancy.
Activities During an Enema: I can't exactly go prancing around with a 6-liter or even a 5-liter enema. Just swinging up off the bed or the floor is quite an exercise in careful movements. Moving around with those volumes can be challenging even with my largest plugs inserted and fully inflated. Easy enough to move around with 2.5-3.0 liters if it is not soapy. Can't run with it, but walking and moving around (vacuuming, for example) are easy enough. Irritating enemas can really limit the activity level. I've taken soapy enemas in my backyard and been able to move around (in the dark of night) if they are less than 3.0 liters but they can be a challenge to get get back into the house if I wait too long (otherwise, I "fertilize" a part of my yard).
Hope this helps, please free to ask for clarification or message me.