I have a question about enemas?

sorry if this is tmi, but I've been slightly constipated for about four days. I've had several small bowel movements, but it feels as if the amount that's coming out is not as much as what should be coming out. I'm going to give myself an enema. I read online that people who use enemas to relieve mild constipation only use those small bulb syringe things and only use a small amount of water, as opposed to the people who use them for routine, thorough cleansings with the big bags and stuff. I have one of those little bulb things for cleaning out ears (it's unused) and I'm planning on just filling it with lukewarm distilled water, injecting a small amount, and then holding it in for maybe 30 seconds before releasing it. Because I'll be using so little water and only holding it in for 30 seconds or so, I won't really have to worry about electrolyte imbalance, right?