Hi everyone! I have just registered at this forum and would like to share some (not very pleasant) experience with glycerin enemas.
Starting from the conclusion: When using osmotic laxatives in enemas, if you didn't get the desired effect, don't rush to increase the dose. It may lead to unpredictable and rather nasty after-effects.
Now in detail. A few days ago I have purchased a pack of bisacodyl suppositories and the holiday period was pretty much the only time when I could experiment with those, so I kind of got carried away and rushed things. First, I inserted two bisacodyl suppositories, waited a few minutes until they melt in my colon and gave myself a 2.5 liter plain water enema. It was not so bad, but I expected I would have more cramps from it than the modest amount of them I actually had. I held it in for like 15 minutes, but after I went to the toilet to expel it, I felt like I could not do it completely.
Then I gave myself a second enema of 250 ml glycerin mixed with 2.25 liters of tap water. That's just 10%, it should be fine, I thought. In fact... First, after I took it all in, I noticed myself feeling a bit... tipsy. I wonder if anyone else gets a similar sensation from glycerin enemas. I held it in for 10 minutes or so too with almost no cramps appearing. After I expelled it, I felt a rather nasty headache, not unlike a hangover. It continued for the next ten minutes or so, and only subsided after I drank some water. After that I gave myself a plain water rinse twice, but the water didn't quite want to get expelled, so to trigger the cramps I gave myself another enema with concentrated solution of baking soda. It was 5 tbsp of baking soda per two liters of water, or so.
Then I finally managed to expel everything, but after that session I started to feel lightheaded and a bit nauseous. I know that this is not an uncommon side effect of enemas, but that lightheadedness continued for three days straight! Only on the fourth day I started to get better, even though I made sure to drink a good amount of water, but now is the fifth day since that session and it has not subsided completely yet.
So yeah, play safe when it comes to osmotic laxatives - looks like they can easily wreak havoc on your electrolyte balance with long-lasting side effects! As for me, I think I will stick with only using glycerin for low-volume enemas to induce cramps for now, that looks more interesting.
P.S. As that bottle of glycerin was a freshly purchased one, I was also anxious about what if it was contaminated with diethylene glycol. It was marked as a food additive, kosher, halal, vegan and whatever not, but given that I live in Eastern Europe, who knows how strictly the regulations are actually followed. Also, few people in the reviews stated that they bought it as a food additive - there were a lot more people buying that for preserving leaves, to soften rubber and whatever not - for technical purposes. Thankfully, I didn't have any definite symptoms of intoxication, so it was all OK, but the anxiety was killing me for three days straight. Whoever buys glycerin from online marketplaces, I believe you might want to check the reviews from those buying it as a food additive.