Reargirl!
I hope you are good with your hands, or your husband/boyfriend is? Because I never had the chance to buy a B**dex, I decided to make my own! You can, too.
The principle is really simple. Take a rigid tube about an inch in diameter about 9 inches long. Plastic is dandy, but it must be RIGID.
Cut from a mountain bike inner tube, a section that includes the inflator valve about one and a half inches from one end. The amount you cut depends on how much you want to shove inside you. More of that later. The cut inner tube should be about an inch to two inches longer than the rigid tube. Slide the bike inner tube over the rigid tube. At the end that will go into your anus, lash the cut end tightly to the rigid tube with dental floss about a quarter inch from the end or the rigid tube. Now make the bike inner tube fold over itself so that your lashing is covered with a fold of inner tube. You should be able to see the rigid tube inside the folded end, level with the fold.
At the other end (the inflator valve end), lash the inner tube to the rigid one again. When you inflate this on your work bench, you will see that the inner tube now stretches over the rigid one and provides a nice, soft rounded end to go into you! You may have to experiment a bit to get lengths right so that it doesn't hang so far over as to close off the hole in the rigid tube. That's where you will send the water, so it has to stay open.
But this basic model has some flaws! It inflates uniformly over its whole length, so if you put it in you it will stretch your anus and not seal well at all. To get over this, you need to put a sleeve over it; but to get this to work just right takes a little more patience. Deflate the gadget you just made, which is your basic inflatable nozzle. Note where the inflator valve rested on the rigid tube. Undo the lashing at the valve end, strip back the inner tube from the place where the valve had rested. Take a small rod like a cocktail swizzle stick or a length of wire at least 16 gauge (AWG or SWG) and long enough to reach from the valve stem almost to the lashing at the business end. Lash this to the rigid tube about where the valve had rested. You only need one lashing, and it doesn't need to be very good. Put the inner tube back in place, and lash it once more.
Cut a section about three to four inches long from the leftover part of your bike inner tube. Lubricate your nozzle with talcum powder, and slide the new section over it from the business end as far as you think it should go into you. when it is in the right position, grab the end furthest from the business end and fold it back on itself to double the thickness. Long nosed pliers are useful for this.
Now try the inlfation again. Better? Yes it is. The sleeved bit doesn't inflate and you have a narrow section that fits inside your anus over the inner and outer sphincters. Without the little gadget you just put inside it, you would not have got any air into the working part at all: your new sleeve would have sealed it off! But the wire/stick/straw/whatever won't let it deal to the rigid tube beneath it. However, now the bit around the inflator valve stem also bulges. Well, you know what to do now, don't you? Right! Cut more sleeves and cover your nozzle until the only part that inlfates its the bit you want inflated.
All you have to do now is to marry up the rigid tube to your enema delivery tube. Any number of possibilities are open to you. Do you have a spare one of those dinky beginner's hard plastic nozzles? Good! Use quick set epoxy putty to set it in place inside the outer end or your new nozzle. Set the putty a little back from the end of the tube. For a perfect seal, and add a dob of silicone after the epoxy has set.
Now experiment with your new toy. If you can adjust its length so that its tip rests against the flap or kink in your rectum that separates it from the descending colon, you will find that it doesn't want to suck itself into you when it is inlfated. It can't - it's already as far in as it will go. For me, this distance is about 5 inches. I usually refine my design so that the sleeve is right up against the valve stem, and the stem itself rests against my perineum. The whole point of this idea is that you need a nozzle that fits YOU, not what some dude looking for profits thinks he can sell.
The inner tube is really flexible and VERY tough. You can expel it while inflated without damage! I can inflate mine to 800-900 ml (about a US pint)! It will eventually spring a leak and you will have to replace it; but I have never had one rupture. They just fade out on me with unwelcome feelings of being let down and heavy leaks!
Johnny