Both will do the same thing for you, as I'm sure your therapist explained, it's about getting yourself in a better posture to have your rectum/anus in the correct position. Both work, by raising your feet up, what you are trying to do is mimic a literal squatting position. Key thing is (whichever you are using) is to keep your back straight (don't slouch, i.e. round your back), or you are defeating the purpose. There are some good photos on line or perhaps your therapist has shown you one. That is one common reaction I see people having. A lot of people (I think - I haven't done any research, lol) tend to lean forward on the toilet. When your feet go up, it will lean you back, a natural counter to this is to slouch. Instead, back sure your butt is back as far as can be on the seat, sit up straight, if you can even try to keep the curve in the smaller of your back, you will get your "lean" there. If you feel you are falling back, lean slightly forward WITH YOUR BACK STRAIGHT. Your therapist can help you with this Also, with the stool, have your feet as wide apart as you can on the stool (it won't be very wide - that's okay, just not close together. Again, imagine an actual squat. You still get your "bottom" in the correct position.

Oh, by the way, I am a physical therapist, although not a specialist in this area professionally, I saw a pelvic floor/GI issues PT for 5 months, learned a LOT from her, and have studied a lot on my own. LOL, I'm explaining my emphasis on posture, posture, posture!

I suppose that is the one selling point of the squatting potty, it wraps around the toilet so you can put your feet wider apart, I'm not sure now much difference that makes though, in terms of getting "the job" done better, for lack of a better word! Maybe you could experiment, and try your son's and let us know!

I've never tried the squatty potty because the stool seems to do what needs to be done for me, or as I said, I literally squat on the toilet seat.

Of course the position is not a miracle, but I can feel how it helps get stool out sometimes, and I supposedly don't even have a pelvic floor problem (however, I don't want to go on too long here), I think it is more complicated than most docs understand. There can be a problems with the coordination of all of the muscles used in defecation, which I had, and only the PTs seem to understand/ address that (at least in my experience). Hence, my new opinion that just about anyone with constipation or altered bowel patterns should see a PT, at least for a consult, because they can teach people things that can really help that docs don't address (or are even aware of).