Syringes?

Is it safe to use regular syringes eg 20ml for enema? Or would the pressure be too high

At such a small volume, I have to think it would be OK

The amount and the pressure are two different terms.

Practically speaking, you can use a pressure of max. 1 m of water column, it is cca 0,1 bar.

The amount may be in liters, depending what you want to achieve. Experience and attention is needed. Someone experienced to show you.

Sure, but 20ml is kinda tiny for enemas.

Also, most 20ml syringes have luer lock tips, making them less than ideal insertables.

I do commonly use 100ml catheter tip irrigation syringes though. Like anything else, don't push ridiculously hard (don't "ram it in there").....but used gently like a bulb, they can be fun and safe

As Miriamvee said, there is a difference between amount and pressure. 20 ml is just a bit over half an oz (liquid), so is probably safe for even the smallest adult rectum.

Pressure, on the other hand, might be a problem depending on several factors. A gas or liquid forced through a restriction (the needle or pointy end of the syringe) will be at the same pressure as anyplace inside the syringe, but the pressure drops extremely fast because it expands after leaving the syringe.

Pressure will be determined by the speed at which the liquid is delivered into the rectum - how fast you push the plunger. Doubtful a 20 ml syringe could build up enough pressure to be harmful, but, that too, would be dependent on the environment - how close to the rectum wall/tissue the tip of the syringe is. Without testing there is no way to really tell how much pressure is produced, but unless the tip is held against tissue it, more than likely, is not dangerous.