I've been looking for a long time for a very comfy butt plug that I can leave in indefinitely. I tried many that failed.
Then I found my perfect plug here: http://siliconenozzles.com/Retention-Nozzles-Plugs_c32.htm
It's the middle plug on the bottom row, the one that looks like it won't come out after you insert it. I ordered it in the 00-02 Extra Soft silicone grade.
I had this plug inserted all day today at the beach while only wearing a tiny v-back bikini swimsuit with 1/2 butt coverage. The Extra Soft silicone flange conforms to the shape of my butt crack, so it's invisible under any swimwear with a wide enough crotch to cover the plug's flange. I trimmed two sides of the flange of my plug a little bit (using scissors) to give me a little cover-up margin back there. I never intended to use the plug like this, but it's my favorite beach plug too now.
Even though it's 3-inches in diameter, this super squishy plug pops right in, even if you are only able to insert a rigid 2-inch or 1.75-inch plug, because it compresses to a much smaller diameter going through your anus and then it pops back out (or tries to) once inside your rectum. Insertion is a little tricky. I can't work it in slowly--too squishy. I use a lot of lube on the plug and plenty of lube in and around my anus, and then I give the plug one quick thrust with considerable force to pop it into me! The super squishy material can't injure you or cause pain. I regularly plug up all night after a nighttime enema session. It never leaks, it seals air tight, and it only comes out when I want it to. It always comes out fairly easily when I pull with moderate force on the flange while squeezing it out with my rectal muscles.
I never have any pain whatsoever with this plug at any time--not from insertion, not from removal, and not from keeping it inserted literally for days. A month ago while I was on a liquids only fast for a week, I did a full colon clean out one night, and then I inserted the plug. I kept it in all night, all the next day, all the following night, and most of the second day--almost 48 hours! It's that comfortable. You forget you have it inserted after a while, but when you squeeze down on it you remember it's there--only because it feels so good. During my 48-hour plugging, I only removed it once, just for a few seconds. That was only to release gas. I immediately cleaned it, lubed it, and popped it back in for another 24 hours!
Has anyone gone longer than 48-hours with a butt plug inserted? What's the Guinness record? I might try to set a new personal best if I feel like fasting for a few days again.